Wind Tunnel Experiments with a Submarine Afterbody Model

Transcription

1 Copy No. Defence Research and Development Canada Recherche et développement pour la défense Canada Wind Tunnel Eperiments with a Submarine Afterbody Model Mike Mackay Defence R&D Canada Technical Memorandum DRDC Atlantic TM March 2003

2 Copy No. Wind Tunnel Eperiments with a Submarine Afterbody Model M. Mackay Defence R&D Canada Atlantic Technical Memorandum DRDC Atlantic TM March 2003

3

4 Abstract Wind tunnel eperiments were done in 1987 and 1988 with a model representing conventional cruciform and X rudder tail arrangements for a submarine. This memorandum presents the principal results of the eperiments, which included total model force and moment measurements and pressure distribution measurements on the tail fins. Résumé Des essais en soufflerie ont été effectués en 1987 et 1988 sur une maquette représentant l arrière-corps cruciforme et le gouvernail en croi d un sous-marin traditionnel. Le mémoire ci-joint présente les principau résultats de ces essais, qui comprennent notamment des mesures des forces et moments eercés sur la maquette et de la distribution des pressions sur les empennages du gouvernail. DRDC Atlantic TM i

5 This page intentionally left blank. ii DRDC Atlantic TM

6 Eecutive Summary Introduction In 1987 and 1988 wind tunnel eperiments were done with a model representing conventional cruciform and X rudder tail arrangements for a submarine. The objectives were to investigate the effectiveness of the different tail fin configurations and to provide verification data for panel code development then underway. Since the results of these eperiments have continued to prove useful, the principal data are documented here in graphical form to facilitate their further application. Significance Tailplane efficiency and fin interactions are still active research topics for the investigation of submarine controllability and manoeuverability. Previous studies are generally restricted to force and moment measurements on systematic families of tail arrangements, whereas these eperiments were done with just two fairly standard configurations, but with the addition of pressure distribution measurements on the fins to enable a more detailed eamination of the flow mechanisms and interactions. The data provide useful validation for CFD code development and contribute to current efforts to model the hydrodynamics of the Victoria class. Principal Results A number of fin interactions are observed in the data; most are attributable to fin separation and junction-induced vortical flows between appendages. The most interesting in terms of controllability and manoeuverability is a loss of control authority with out-of-plane incidence in the X rudder configuration. Further Investigations No future work is planned with this model. M. Mackay, 2003, Wind Tunnel Eperiments with a Submarine Afterbody Model, DRDC Atlantic TM Defence R&D Canada Atlantic. DRDC Atlantic TM iii

7 Sommaire Introduction En 1987 et 1988, des essais en soufflerie ont été effectués sur une maquette représentant l arrière-corps cruciforme et le gouvernail en croi d un sous-marin traditionnel. Ces essais avaient pour objet d étudier l efficacité de différentes configurations d empennages de gouvernail et de recueillir des données de vérification pour le développement des codes de panneau en cours à cette époque-là. Puisque les résultats de ces essais continuent à se révéler utiles, leurs principales données ont été reproduites ici sous forme de graphiques pour en faciliter l utilisation à de nouvelles applications. Importance L efficacité de l empennage horizontal du gouvernail et l interaction entre les empennages font encore l objet de recherches dans le cadre des études sur la pilotabilité et la manuvrabilité des sous-marins. Lors des essais antérieurs, on s était généralement limité à mesurer les forces et les moments eercés sur des familles systématiques de configurations de gouvernails, alors que les essais en question n ont porté que sur deu configurations de gouvernails relativement standard et l addition des mesures sur la distribution des pressions sur les empennages a permis d étudier plus en détail les mécanismes d écoulement et de leur interaction. Ces données s avèrent encore utiles pour le développement actuel des codes CFD et leur validation éventuelle, et contribuent au efforts actuels modéliser les caractéristiques hydrodynamiques de la classe Victoria. Principau résultats Un certain nombre d interactions entre empennages peuvent être observées sur les données; la plupart de ces interactions sont attribuables à la séparation entre les empennages et au écoulements tourbillonnaires au point de jonction des empennages. Ce qui est le plus intéressant en termes de pilotabilité et manuvrabilité estlapertede réponse des commandes avec incidence hors-plan de la configuration en croi du gouvernail. Poursuite des recherches Aucune nouvelle étude n est prévue sur ce modèle. M. Mackay, 2003, Wind Tunnel Eperiments with a Submarine Afterbody Model, DRDC Atlantic TM R&Dpourladéfence Canada Atlantique. iv DRDC Atlantic TM

8 Table of Contents Abstract... i Résumé... i Eecutive Summary... iii Sommaire... iv Table of Contents... v List of Figures... vi 1 Introduction Model and Eperimental Procedures Setup Runs Report Cruciform Model X Rudder Model Report Cruciform Model X Rudder Model Concluding Remarks... 7 References... 9 Anne A. Report 504 Run Summary Anne B. Report 526 Run Summary Nomenclature DRDC Atlantic TM v

9 List of Figures Figure 1. Model configurations Figure 2. Body geometry Figure 3. Fin geometry Figure 4. Pressure tap geometry Figure 5. Cruciform model in the wind tunnel Figure 6. The model opened to install Scanivalve units Figure 7. Body alone in yaw, no transition trips Figure 8. Transition tripping variations, cruciform model in yaw Figure 9. Reynolds number variations, cruciform model in yaw Figure 10. Oil flow visualization Figure 11. Report 504 Cruciform model rudder effectiveness: forces and moments Figure 12. Report 504 Cruciform model rudder effectiveness: sideforce crossplot Figure 13. Report 504 Cruciform model sternplane shadowing: force and moment Figure 14. Report 504 Cruciform model sternplane effectiveness, δ r =0 : force and moment Figure 15. Report 504 Cruciform model sternplane effectiveness, δ r =0 : normal force crossplot Figure 16. Report 504 Cruciform model sternplane effectiveness, δ r = 30 : forces and moments Figure 17. Report 504 Cruciform model sternplane effectiveness, δ r = 30 : normal force crossplot Figure 18. Report 504 X rudder model rudder effectiveness: force and moment Figure 19. Report 504 X rudder model rudder effectiveness: sideforce crossplot Figure 20. Report 526 Cruciform model rudder effectiveness: pressure distributions for δ r = Figure 21. Report 526 Cruciform model rudder effectiveness: sideforce comparison with Report 504 at δ r = Figure 22. Report 526 Cruciform model rudder effectiveness: pressure distributions for δ r = Figure 23. Report 526 Cruciform model rudder effectiveness: pressure distributions for δ r = vi DRDC Atlantic TM

10 Figure 24. Figure 25. Figure 25. Figure 27. Figure 28. Figure 29. Figure 30. Figure 31. Figure 32. Figure 33. Figure 34. Figure 35. Figure 36. Figure 37. Figure 38. Figure 39. Figure 40. Figure 41. Figure 42. Report 526 Cruciform model rudder effectiveness: pressure distributions for δ r = Report 526 Cruciform model rudder effectiveness: pressure distributions for δ r = Report 526 Cruciform model rudder effectiveness: integrated pressures Report 526 Cruciform model sternplane shadowing: pressure distributions for δ s = Report 526 Cruciform model sternplane shadowing: integrated pressures Report 526 Cruciform model sternplane effectiveness: pressure distributions for δ s = Report 526 Cruciform model sternplane effectiveness: pressure distributions for δ s = Report 526 Cruciform model sternplane effectiveness: pressure distributions for δ s = Report 526 Cruciform model sternplane effectiveness: pressure distributions for δ s = Report 526 Cruciform model sternplane effectiveness: pressure distributions for δ s = Report 526 Cruciform model sternplane effectiveness: integrated pressures Report 526 Cruciform model sternplane effectiveness, δ r = 30 : pressure distributions for δ s = Report 526 Cruciform model sternplane effectiveness, δ r = 30 : pressure distributions for δ s = Report 526 Cruciform model sternplane effectiveness, δ r variations, integrated pressures Report 526 Cruciform model sternplane effectiveness, δ r variations, force and moment Report 526 X rudder model rudder effectiveness: pressure distributions for δ r = Report 526 X rudder model rudder effectiveness: pressure distributions for δ r = Report 526 X rudder model rudder effectiveness: pressure distributions for δ r = Report 526 X rudder model rudder effectiveness: integrated pressures DRDC Atlantic TM vii

11 Figure 43. Report 526 X rudder model rudder effectiveness: force and moment Figure 44. Report 526 X rudder model rudder shadowing, δ s =+10 : pressure distributions Figure 45. Report 526 X rudder model rudder shadowing, δ s =+20 : pressure distributions Figure 46. Report 526 X rudder model rudder shadowing: integrated pressures Figure 47. Report 526 X rudder model rudder shadowing: forces viii DRDC Atlantic TM

12 1 Introduction Eperiments with a model representing the etreme afterbody of a submarine were conducted during 1987 and 1988 in the 2 3 metre wind tunnel of the National Aeronautical Establishment (NAE now IAR, the Institute for Aerospace Research, a component of NRC, the National Research Council of Canada) in Ottawa. The model was equipped with rudders and sternplanes, but no propeller. These eperiments had two purposes: to investigate the effectiveness of the aft appendages, or fins, in a conventional cruciform or X-rudder configuration, and to provide data for the verification of panel codes which were under development at that time. While the data have been selectively used in these and other applications, the overall results of the eperiments have never been formally published. This memorandum corrects that omission. Submarine rudders and sternplanes are characterised by their low aspect ratio and close proimity to each other. The effect of this proimity has not been widely discussed in the open literature. With the adoption of increasingly comple stern arrangements (e.g., pentaform and heptaform tails), fin interactions are potentially even more important than before. Published research has concentrated on interactions between the fins and the body, the most familiar eample for submarines being Dempsey s towing tank eperiments with a cruciform tail on a slender hull [1]. A brief overview of work in this area is given in Mackay et al [2]. Testing tail arrangements on a full hull results in either a large model or one with quite small fins. The latter may be subject to scaling difficulties. For interactions between the fins, both require measuring relatively small forces in the presence of much larger ones. To alleviate these problems it was decided to use an etensively foreshortened hull. There are precedents for this in eperiments in which a rudder with various flap configurations was tested on a submarine afterbody half-model at the University of Maryland [3], and a number of all-moving rudders were similarly tested at the Georgia Institute of Technology [4]. Rather than eamining the effect of a number of geometrical parameters, the NAE wind tunnel eperiments investigated just two representative configurations a cruciform and a X rudder stern in some detail. They were done in two series, referred to in NAE nomenclature as Report 504 and Report 526 (note: these are not actual test reports). The first, Report 504 done in 1987, concentrated on force measurements using the wind tunnel main balance; the second, Report 526 done in 1988, concentrated on pressure distribution measurements on selected fins for a subset of runs from the first series. The model and eperimental procedures are discussed in more detail in the net section. This memorandum is essentially a data report; it does not present detailed analysis. Some miscellaneous setup runs that were done at the start of the Report 504 series are described in section 3, the Report 504 data proper are discussed in section 4, and the Report 526 data are discussed in section 5. DRDC Atlantic TM

13 2 Model and Eperimental Procedures The model comprised an aisymmetric body to which four fins, representing the stern appendages, were added. The cruciform configuration had asymmetric upper and lower flapped rudders and flapped horizontal sternplanes. The X rudder configuration had four identical rudders with an all-moving outer section; the body was rotated 45 degrees. The two configurations are sketched in figure 1, and the body and fin geometries defined in figures 2 and 3 respectively. Note that dimensions are given in terms of the diameter, D, of the submarine hull for which the body in these eperiments represents the aft-most tail region. This hull is the Standard Submarine Model, which has been etensively tested in a number of other facilities [5]; the upper rudder in the cruciform model has the tailplane planform used in the Standard Model parent configuration. Additional upper and lower rudders, one sternplane, and one X rudder were provided with pressure taps as sketched in figure 4. These fins were used in the Report 526 eperiments. The model was machined from aluminium with stainless steel used in highly-stressed areas. The tail of the body was truncated slightly in order to mount the model on the main tunnel balance sting support, see figure 5. For pressure measurements, three Scanivalve (Scanivalve Corp., Liberty Lake, WA) 48-port J units were installed inside the body, figure 6. The 2 3 metre wind tunnel as it was at the time of these eperiments is described in reference [6]. Today, the working section and main balance are unchanged, but data acquisition systems and instrumentation have been etensively upgraded. Tunnel and systems specifications are posted at 7.html; the following are most relevant to the tests reported here: flow speed uniformity in the working section 0.7%, turbulence level 0.14%, main balance lift range ±6670 N, drag and sideforce ±4450 N, and moments ±2710 N m, all with an accuracy of ±0.1% of full scale. Model pitch, α, andyaw, β, were obtained by rotating the tunnel turntable with the model rotated to one side, and upright, respectively. (We do not need to distinguish here between rotations in model or tunnel aes because only pure pitch or pure yaw were used.) Tunnel blockage and other corrections were applied by the data acquisition software; a small tare associated with drag on the eposed sting and its support (on the left hand side of figure 5) could be ignored because accurate drag measurement was not an objective of these eperiments. The standard convention for coordinates, loads, and control deflections is followed in this memorandum; see the Nomenclature and reference [7]. 2 DRDC Atlantic TM

14 Forces and moments are reported in coefficient form: C X = X qs C Y = Y qs C Z = Z qs C K = K qsb C M = M qsc C N = N qsc where (X, Y, Z, K, M, N) are the aial, side, and normal forces and rolling, pitching, and yawing moments; C X, etc., are the corresponding nondimensional coefficients; q is the tunnel dynamic pressure; S is a reference area; and b and c arespanwiseand chordwise reference lengths. The same reference dimensions are used throughout: S =3871 m 2, b = m, and c = m. The notation C X,etc.,hasbeen used to distinguish the values reported here from the more familiar X, etc., that are based on powers of hull length. The origin for moment measurements is on the body ais, m forward of the untruncated tail point. Tunnel dynamic pressure, which varied slightly from run to run, corresponded to a tunnel speed of about 56 m/s; the nominal setting for q was 40 psf, or about kpa. In Report 504 tests, two of the fin attachments were strain-gauged to measure bending and torque. These measurements alone did not fully define the fin loads, and were used to qualitatively confirm the onset of stall; they are not reported here. Pressures are reported in standard coefficient form: C P = P P 0 q where P is local pressure and P 0 is the freestream static pressure. For each row of pressure taps, the coefficient of the normal load, C ζ, was obtained by integrating C P for a unit chordlength along the row. 3 Setup Runs The setup period at the beginning of the Report 504 eperiments comprised a number of tests outside the main program: the body-alone, the effect of transition trips applied to the body and fins, the effect of taping flap and wing root gaps, Reynolds number variations, and a limited number of flow visualization runs. Transition trips were also tried in combination with the other parameters. DRDC Atlantic TM

15 Body-alone data were required to derive values of tailplane efficiency [2]. Forces and moment for the body in yaw, with no transition trips, are shown in Figure 7. The aial force data suggest that some separation is taking place at yaw angles over 20 to 25 degrees, but this is not apparent in the other parts of the figure nor is the asymmetry in yaw that is seen in the aial force, notably for run The irregularities in figure 7(c) perhaps point mainly to the difficulty of making repeatable aial force measurements with the sting model mount. Three transition tripping schemes were tested; a comparison of the tunnel balance measurements is shown in figure 8. In all cases there is evidence of stall, varying in symmetry and abruptness, at yaw angles greater than ±15 degrees. (The rolling moment in figure 8(d) originates in asymmetry between the upper and lower rudders.) It was made standard procedure in subsequent tests to apply a 5 mm band of #80 grit to the fin leading edges with no transition tripping on the body. Taping the flap and wing root gaps made effectively no difference to the tunnel balance measurements within eperimental uncertainty. In subsequent tests these gaps were taped only for the flow visualization runs, to prevent ecessive oil build-up inside the model. Tunnel balance measurements were compared at Reynolds numbers, based on body length, of 2.25, 4.5 and 13.5 million; one such comparison is shown in figure 9. There is an offset in some of the data, which likely originates from model support compliance at the different dynamic pressures, but little to suggest a significant direct dependence on Reynolds number. At some combinations of high dynamic pressure and high incidence, the model eperienced serious flutter and vibration. To mitigate the problem, all subsequent tests were done at a body length Reynolds number of 4.5 million, equivalent to about 17 million on the full Standard Model hull. Although that figure is conventionally considered sufficiently high for model testing, the corresponding fin chord Reynolds numbers were still in the critical region, about one million, which contributed to the decision to employ fin leading edge transition tripping. Oil and pigment flow visualization was done with the cruciform model at zero incidence, shown in figure 5, and at yaw angles of 10, 15, 20, and 25 degrees, illustrated in figure 10, all with zero rudder and plane angles. Figure 10 shows a considerable change in the limiting streamline patterns on the rudder from one yaw angle to another. These eperiments also demonstrate strong junction flow interactions, which are also seen at similar Reynolds numbers on full submarine models [8]. 4 DRDC Atlantic TM

16 4 Report 504 Report 504 runs are summarized in anne A. 4.1 Cruciform Model The principal forces and moments for the rudder effectiveness series are shown in figure 11; sideforce is cross plotted against rudder (flap) deflection in figure 12. A fairly abrupt stall at 15 degrees coincides with the appearance of etensive regions of reverse flow on the rudders, see figure 10. In the crossplot, figure 12, it appears as a sideforce limit on each set of yaw angle data. Note in figure 12 that yaw is indicated as β n to indicate the nominal, rather than actual, yaw angle, and the data have not been interpolated accordingly. This convention is used in the other crossplot figures in this report. Rudder and sternplane shadowing eperiments comprise control deflections in one plane while incidence is varied in the other. Without any coupling, the control force should be constant for a given deflection, but there is generally a small dependence on incidence, often attributed to one (or two, in the case of X rudders) of the lee side fins being in the wake of the hull. Figure 13 shows that for sternplane deflections the control force and associated moment are essentially independent of yaw until rudder stall, which, as previously noted, occurs at a yaw angle of about 15 degrees. (A disturbance on the lee side sternplane resulting from rudder stall is evident in the sternplane shadowing runs done for Report 526, e.g., in figure 26(e).) Sternplane effectiveness results for zero rudder deflection are shown in figure 14, and the normal force crossplot in figure 15. The sternplanes do not stall in the pitch range ±20 degrees, but the crossplot suggests possible trailing edge flow separation on the flap at deflections above 25 degrees. Thesternplaneeffectiveness normal force and pitching moment at a rudder angle of 30 degrees, figures 16 and 17, are very similar to the previous results. However, some coupling interactions can be observed in the other loads, notably sideforce. 4.2 X Rudder Model The only X rudder model measurements made in Report 504 were of rudder effectiveness, figures 18 and 19. The δ r convention for X rudders is illustrated in the Nomenclature. There is an indication of stall occuring at about 20 degrees, but it is less abrupt than was observed for the Cruciform Model rudders. The slope of the yawing moment curve ehibits a variation with control deflection, figure 18(b). DRDC Atlantic TM

17 5 Report 526 Report 526 runs are summarized in Anne B. In graphing pressure coefficients in figure 20 and following, the data at alternating incidence angles have been omitted in order to avoid confusion. In a few of the figures, figure 20(b) for eample, there are apparent disturbances near the leading edge that may be artifacts the leading edge pressure taps are more susceptible than the others to blockage from debris ingestion. Main balance force and moment measurements were generally the same, within eperimental error, as the equivalent measurements presented for Report 504 and are only reported here in one or two instances. 5.1 Cruciform Model Pressure measurements with zero flap deflections clearly show rudder stall at yaw angles of 15 degrees and above, figure 20. Figure 20(d) data at β n = ±10 suggest that this may initiate with trailing edge separation, which generally results in a gentle stall. However, sideforce data for the Report 504 and Report 526 runs in this configuration show a range of stall characteristics. Figure 21 shows that stall characteristics are not entirely consistent in either test program; for eample, in run , stall is relatively smooth and somewhat delayed at positive yaw angles compared with negative yaw angles. Figures 20(e) and (f) show some trailing edge separation on the sternplanes as yaw increases, following rudder stall above 15 degrees (figure 11). Pressure distributions for the rest of the rudder effectiveness series are shown in figures 22 to 25. Sternplane trailing edge separation is more pronounced on the lee side plane (positive β) in parts (e) and (f) of these figures. Integrated rudder pressures, figure 26(a) to (d), are consistent with the early stall characteristic seen for run in figure 21. The integrated sternplane pressures, figure 26(e) and (f), illustrate the effect of yaw on lift in the vertical plane. Only δ s =+10 data were available from the sternplane shadowing runs, figures 27 and 28. The sternplane effectiveness pressure data, figures 29 to 33, show epected sternplane lift/stall characteristics. The lower rudder consistently ehibits trailing edge separation at the outer row of pressure taps at a pitch angle of 20 degrees. On the lower rudder there is also enhanced (horizontal) lift at the inner row of pressure taps, at large positive pitch when δ s is negative, and large negative pitch when δ s is positive. A similar effect is seen on the upper rudder for δ s = 10, figure 29(a). Integrated pressures, figure 34, are consistent with the Report 504 observation that the sternplanes effectively do not stall within the pitch range. 6 DRDC Atlantic TM

18 Sternplane effectiveness for a non-zero rudder angle was done for δ s =+10 and +20 at a rudder angle of 30 degrees, figures 35 to 37. The lower rudder outer row pressure distributions are clearly influenced by pitch angle, whereas those at other locations ehibit much smaller effects. The sternplane characteristics are as epected. The small effect of rudder angle on sternplane integrated pressures, figure 37(e) and (f), is not so apparent in the measured forces, figure X Rudder Model Rudder effectiveness pressure data are plotted on figures 39 to 42. The pressure-tapped rudder was in the upper port position, so it was to windward for positive yaw, and to the lee side for negative. Note in figure 40 and following that the inner row of pressure taps is on the fied inner portion of the X rudder, while the middle and outer rows are on the moving outer portion.the difference can be seen in the integrated pressures, figure 42, but is further integrated out in the measured sideforce data, figure 43. X rudder shadowing pressure data are plotted on figures 44 to 46. The measured force data in figure 47 show a severe reduction in the control authority (of δ s in this case) with respect to range of incidence in the other plane (i.e., yaw) as the control deflection increases. Thus, at δ s =+10, full sternplane control authority is maintained over a range of ±10 degrees of yaw, while for δ s =+20 it is maintained over only ±5 degrees. This is seen in the pressure data by comparing the pressures for δ s =+10 at 10 and 20 degrees of yaw, for eample (figure 44). For the middle and outer rows of pressure taps there is probable onset of leading edge separation at β =+10 leading to complete stall at β =+20. These pressure distribution characteristics are to some etent carried over to the inner row. 6 Concluding Remarks The overall force and moment data and pressure distributions discussed here represent a reasonably comprehensive survey of fin interactions for the two configurations tested. A number of different interactions were observed, the most interesting being a loss of control authority with out-of-plane incidence in the X rudder configuration. With the foreshortened hull, simple shadowing effects were, as epected, in general quite small. Although this memorandum does not attempt detailed analysis of the results, we can note that fin separation and junction-induced vortical flows between appendages are likely responsible for many of the observed interactions. Additional flow visualization runs may have allowed a more positive identification of the flow mechanisms involved. DRDC Atlantic TM

19 While the setup runs indicated little effect of Reynolds number on the measured forces and moments, its effects cannot be easily dismissed, since separation remains sensitive to it even at supercritical Reynolds numbers on the fins, and etrapolation of the eperimental results to full scale is uncertain. It will therefore be useful if future work on tail appendage interactions includes a more detailed eamination of the effect of Reynolds number on the interactions observed in these eperiments. 8 DRDC Atlantic TM

20 References 1. Dempsey, E.M. (1977). Static Stability Characteristics of a Systematic Series of Stern Control Surfaces on a Body of Revolution. (DTNSRDC Report ). David Taylor Naval Ship Research and Development Center. 2. Mackay, M., Bohlmann, H.J., and Watt, G.D. (2002). Modeling Submarine Tailplane Efficiency. In RTO Meeting on Challenges in Dynamics, System Identification, Control and Handling Qualities for Land, Air, Sea, and Space Vehicles. (RTO MP 095). Paris: NATO RTO. 3. Bowers, A.A. (1959). Wind Tunnel Investigation of the Characteristics of a Flapped Control Surface Mounted on a Simulated Submarine Hull. (U of M Wind Tunnel Report No. 259). University of Maryland. 4. Harper, J.J. and Simitses, G.J. (1959). Wind Tunnel Investigation of the Effect of a Simulated Submarine Hull on the Aerodynamic Characteristics of All-Movable Control Surfaces having NACA 0015 Airfoil Sections. (GIT Report to BuShips on Engineering Eperimental Station Project A-439). Georgia Institute of Technology. 5. Mackay, M. (2002). The Standard Submarine Model: A Survey of Static Eperiments and Semiempirical Predictions. (DRDC Report in review). Defence R&D Canada Atlantic. 6. Brown, T.R. and Hansen, K. (1987). A User Manual for Aeronautical Research Facilities in Building M 2. (Comprising Laboratory Reports LTR LA 285, LTR LA 286, and LTR LA 287). Low Speed Aerodynamics Laboratory, National Research Council. 7. Gertler, M. and Hagen, G.R. (1967). Standard Equations of Motion for Submarine Simulation. (NSRDC Report 2510). Naval Ship Research and Development Center. 8. Whickens, R.H. and de Souza, F. (1993). Flow Visualization Analysis and Flow Field Survey on the DREA Mark I Generic Submarine Model. (NRC LTR HA 94). NRC Institute for Aerospace Research. LIMITED DISTRIBUTION. DRDC Atlantic TM

21 This page intentionally left blank. 10 DRDC Atlantic TM

22 A Upper Rudder A A Lower Rudder B B B Sternplanes A B (a) Cruciform Model C C X Rudders C C (b) X Rudder Model Figure 1. Model configurations: (a) cruciform, (b) X rudder. DRDC Atlantic TM

23 r' Model Conceptual Submarine Afterbody ' D Tail (Parabola) Region Nose (Ellipse) Region The two body regions are defined by the following equations. Tail ( 4D/3): r D = D Nose ( > 4D/3): r D = D D The total body length is D and its maimum diameter is D. The conceptual submarine afterbody results from continuing the tail equation out to =3D, followed by parallel midbody. Figure 2. Body geometry. 12 DRDC Atlantic TM

24 D C B A E Upper Rudder and Sternplanes D C B A E F A B E F X Rudders D C Lower Rudder The dimensions in this figure are tabulated here in units of D: A B C D E F Upper Rudder Lower Rudder Sternplanes X Rudders Dimension B is to the hinge line for flapped fins, and to the pivot line for X rudders. All fins have NACA 0015 sections parallel to the body ais. Figure 3. Fin geometry. DRDC Atlantic TM

25 Outer Upper Rudder and Sternplane Inner Outer Middle Inner X Rudder Inner Outer Lower Rudder Pressure taps were laid out in two or three rows as sketched above. The location of therowsisdefined as a percentage of the leading or trailing edge (l.e. or t.e.), measured from the root: Inner Middle Outer %l.e. %t.e. %l.e. %t.e. % l.e. %t.e. Upper Rudder Lower Rudder Sternplane X Rudder Along each row, taps were located on both surfaces at the following percentages aft of the leading edge:, 1.25, 2.5, 5, 7.5, 10, 15, 20, 25, 30, 40, 50, 60, 70, 80, 85, 90, and 95% (the last on one surface only). A few taps were omitted in the region of a flap hinge or where internal connections were difficult. Figure 4. Pressure tap geometry. 14 DRDC Atlantic TM

26 Figure 5. Cruciform model in the wind tunnel. (The photograph was taken after an oil flow visualization run at zero incidence.) Figure 6. The model opened to install Scanivalve units. DRDC Atlantic TM

27 Run Run C Y - (a) β (deg.) Run Run C N - (b) β (deg.) Figure 7. Body alone in yaw, no transition trips: (a) sideforce, and (b) yawing moment (continued). 16 DRDC Atlantic TM

28 Run Run C X (c) β (deg.) Figure 7. (cont.) Body alone in yaw, no transition trips: (c) aial force. DRDC Atlantic TM

29 5 4 3 No transition trips Grit on nose and fins Grit on fins; tape at ma. body dia. Grit on fins only 2 1 C Y (a) β (deg.) No transition trips Grit on nose and fins Grit on fins; tape at ma. body dia. Grit on fins only C N (b) β (deg.) Figure 8. Transition tripping variations, cruciform model in yaw: (a) Sideforce, (b) Yawing Moment (continued). 18 DRDC Atlantic TM

30 No transition trips Grit on nose and fins Grit on fins; tape at ma. body dia. Grit on fins only -0.1 C X (c) β (deg.) No transition trips Grit on nose and fins Grit on fins; tape at ma. body dia. Grit on fins only 0 C K (d) β (deg.) Figure 8. (cont.) Transition tripping variations, cruciform model in yaw: (c)aialforce,(d)rollingmoment. DRDC Atlantic TM

31 5 4 3 R e = R e = R e = C Y (a) β (deg.) R e = R e = R e = C N (b) β (deg.) Figure 9. Reynolds number variations, cruciform model in yaw: (a) Sideforce and (b) Yawing Moment; R e is based on body length (continued). 20 DRDC Atlantic TM

32 R e = R e = R e = C X (c) β (deg.) R e = R e = R e = C K (d) β (deg.) Figure 9. (cont.) Reynolds number variations, cruciform model in yaw: (c) Aial Force and (d) Rolling Moment; R e is based on body length. DRDC Atlantic TM

33 Figure 10. Oil flow visualization: cruciform model at (upper) 10 degrees and (lower) 15 degrees yaw (continued). 22 DRDC Atlantic TM

34 Figure 10. (cont.) Oil flow visualization: cruciform model at (upper) 20 degrees and (lower) 25 degrees yaw. DRDC Atlantic TM

35 δ r = +10 o δ r = + 5 o δ r = 0 o δ r = 5 o δ r = 10 o δ r = 15 o δ r = 20 o δ r = 25 o δ r = 30 o δ r = 35 o C Y (a) β (deg.) C N δ r = +10 o δ r = + 5 o δ r = 0 o δ r = 5 o δ r = 10 o δ r = 15 o δ r = 20 o δ r = 25 o δ r = 30 o δ r = 35 o (b) β (deg.) Figure 11. Report 504 Cruciform model rudder effectiveness: (a) sideforce and (b) yawing moment vs drift angle (continued). 24 DRDC Atlantic TM

36 C X δ r = +10 o δ r = + 5 o δ r = 0 o δ r = 5 o δ r = 10 o δ r = 15 o δ r = 20 o δ r = 25 o δ r = 30 o δ r = 35 o (c) β (deg.) C K δ r = +10 o δ r = + 5 o δ r = 0 o δ r = 5 o δ r = 10 o δ r = 15 o δ r = 20 o δ r = 25 o δ r = 30 o δ r = 35 o (d) β (deg.) Figure 11. (cont.) Report 504 Cruciform model rudder effectiveness: (c) aial force and (d) rolling moment vs drift angle. DRDC Atlantic TM

37 C Y β n = 20 o β n = 17.5 o β n = 15 o β n = 12.5 o β n = 10 o β n = 7.5 o β n = 5 o β n = 2.5 o β n = 0 o β n = o β n = + 5 o β n = o β n = +10 o β n = o β n = +15 o β n = o β n = +20 o δ r (deg.) Figure 12. Report 504 Cruciform model rudder effectiveness: sideforce vs rudder angle. 26 DRDC Atlantic TM

38 - C Z δ s = 10 o δ s = 5 o δ s = 0 o δ s = + 5 o δ s = +10 o δ s = +15 o δ s = +20 o δ s = +25 o δ s = +30 o δ s = +35 o (a) β (deg.) C M δ s = 10 o δ s = 5 o δ s = 0 o δ s = + 5 o δ s = +10 o δ s = +15 o δ s = +20 o δ s = +25 o δ s = +30 o δ s = +35 o (b) β (deg.) Figure 13. Report 504 Cruciform model sternplane shadowing: (a) normal force and (b) pitching moment vs drift angle. DRDC Atlantic TM

39 C Z (a) δ s = 10 o δ s = 5 o δ s = 0 o δ s = + 5 o δ s = +10 o δ s = +15 o δ s = +20 o δ s = +25 o δ s = +30 o δ s = +35 o α (deg.) C M δ s = 10 o δ s = 5 o δ s = 0 o δ s = + 5 o δ s = +10 o δ s = +15 o δ s = +20 o δ s = +25 o δ s = +30 o δ s = +35 o (b) α (deg.) Figure 14. Report 504 Cruciform model sternplane effectiveness, δ r =0 : (a) normal force and (b) pitching moment vs pitch angle. 28 DRDC Atlantic TM

40 C Z α n = 20 o α n = 17.5 o α n = 15 o α n = 12.5 o α n = 10 o α n = 7.5 o α n = 5 o α n = 2.5 o α n = 0 o α n = +2.5 o α n = +5 o α n = +7.5 o α n = +10 o α n = o α n = +15 o α n = o α n = +20 o δ s (deg.) Figure 15. Report 504 Cruciform model sternplane effectiveness, δ r =0 : normal force vs sternplane angle. DRDC Atlantic TM

41 C Z (a) δ s = 10 o δ s = 5 o δ s = 0 o δ s = + 5 o δ s = +10 o δ s = +15 o δ s = +20 o δ s = +25 o δ s = +30 o δ s = +35 o α (deg.) C M δ s = 10 o δ s = 5 o δ s = 0 o δ s = + 5 o δ s = +10 o δ s = +15 o δ s = +20 o δ s = +25 o δ s = +30 o δ s = +35 o (b) α (deg.) Figure 16. Report 504 Cruciform model sternplane effectiveness, δ r = 30 : (a) normal force and (b) pitching moment vs pitch angle (continued). 30 DRDC Atlantic TM

42 C X δ s = 10 o δ s = 5 o δ s = 0 o δ s = + 5 o δ s = +10 o δ s = +15 o δ s = +20 o δ s = +25 o δ s = +30 o δ s = +35 o (c) α (deg.) C K δ s = 10 o δ s = 5 o δ s = 0 o δ s = + 5 o δ s = +10 o δ s = +15 o δ s = +20 o δ s = +25 o δ s = +30 o δ s = +35 o (d) α (deg.) Figure 16. (cont.) Report 504 Cruciform model sternplane effectiveness, δ r = 30 : (c) aial force and (d) rolling moment vs pitch angle (continued). DRDC Atlantic TM

43 C Y δ s = 10 o δ s = 5 o δ s = 0 o δ s = + 5 o δ s = +10 o δ s = +15 o δ s = +20 o δ s = +25 o δ s = +30 o δ s = +35 o (e) α (deg.) C N δ s = 10 o δ s = 5 o δ s = 0 o δ s = + 5 o δ s = +10 o δ s = +15 o δ s = +20 o δ s = +25 o δ s = +30 o δ s = +35 o (f) α (deg.) Figure 16. (cont.) Report 504 Cruciform model sternplane effectiveness, δ r = 30 : (e) sideforce and (f) yawing moment vs pitch angle. 32 DRDC Atlantic TM

44 C Z α n = 20 o α n = 17.5 o α n = 15 o α n = 12.5 o α n = 10 o α n = 7.5 o α n = 5 o α n = 2.5 o α n = 0 o α n = o α n = + 5 o α n = o α n = +10 o α n = o α n = +15 o α n = o α n = +20 o δ s (deg.) Figure 17. Report 504 Cruciform model sternplane effectiveness, δ r = 30 : normal force vs sternplane angle. DRDC Atlantic TM

45 C Y δ r = +10 o δ r = + 5 o δ r = 0 o δ r = 5 o δ r = 10 o δ r = 15 o δ r = 20 o δ r = 25 o δ r = 30 o δ r = 35 o (a) β (deg.) C N δ r = +10 o δ r = + 5 o δ r = 0 o δ r = 5 o δ r = 10 o δ r = 15 o δ r = 20 o δ r = 25 o δ r = 30 o δ r = 35 o (b) β (deg.) Figure 18. Report 504 X rudder model rudder effectiveness: (a) sideforce and (b) yawing moment vs drift angle. 34 DRDC Atlantic TM

46 C Y β n = 20 o β n = 17.5 o β n = 15 o β n = 12.5 o β n = 10 o β n = 7.5 o β n = 5 o β n = 2.5 o β n = 0 o β n = o β n = + 5 o β n = o β n = +10 o β n = o β n = +15 o β n = o β n = +20 o δ r (deg.) Figure 19. Report 504 X rudder model rudder effectiveness: sideforce vs rudder angle. DRDC Atlantic TM

47 β n = 30 o β n = 25 o β n = 20 o β n = 15 o β n = 10 o β n = 5 o β n = 0 o β n = + 5 o β n = +10 o (a) β n = 30 o β n = 25 o β n = 20 o β n = 15 o β n = 10 o β n = 5 o β n = 0 o β n = + 5 o β n = +10 o (b) Figure 20. Report 526 Cruciform model rudder effectiveness; δ r =0 : (a) upper rudder, inner row, and (b) upper rudder, outer row (continued). 36 DRDC Atlantic TM

48 β n = 30 o β n = 25 o β n = 20 o β n = 15 o β n = 10 o β n = 5 o β n = 0 o β n = + 5 o β n = +10 o - (c) β n = 30 o β n = 25 o β n = 20 o β n = 15 o β n = 10 o β n = 5 o β n = 0 o β n = + 5 o β n = +10 o - (d) Figure 20. (cont.) Report 526 Cruciform model rudder effectiveness; δ r =0 : (c) lower rudder, inner row, and (d) lower rudder, outer row (continued). DRDC Atlantic TM

49 - β n = 30 o β n = 25 o β n = 20 o β n = 15 o β n = 10 o β n = 5 o β n = 0 o β n = + 5 o β n = +10 o (e) β n = 30 o β n = 25 o β n = 20 o β n = 15 o β n = 10 o β n = 5 o β n = 0 o β n = + 5 o β n = +10 o (f) Figure 20. (cont.) Report 526 Cruciform model rudder effectiveness; δ r =0 : (e) starboard sternplane, inner row, and (f) starboard sternplane, outer row. 38 DRDC Atlantic TM

50 5 4 3 Run Run Run C Y β (deg.) Figure 21. Report 526 Cruciform model rudder effectiveness: comparison of equivalent Report 504 and Report 526 runs at δ r =0. DRDC Atlantic TM

51 β n = 30 o β n = 20 o β n = 10 o β n = 0 o β n = +10 o β n = +20 o β n = +30 o - (a) β n = 30 o β n = 20 o β n = 10 o β n = 0 o β n = +10 o β n = +20 o β n = +30 o - (b) Figure 22. Report 526 Cruciform model rudder effectiveness; δ r =+10 : (a) upper rudder, inner row, and (b) upper rudder, outer row (continued). 40 DRDC Atlantic TM

52 β n = 30 o β n = 20 o β n = 10 o β n = 0 o β n = +10 o β n = +20 o β n = +30 o - (c) β n = 30 o β n = 20 o β n = 10 o β n = 0 o β n = +10 o β n = +20 o β n = +30 o - (d) Figure 22. (cont.) Report 526 Cruciform model rudder effectiveness; δ r =+10 : (c) lower rudder, inner row, and (d) lower rudder, outer row (continued). DRDC Atlantic TM

53 -2.5 β n = 30 o β n = 20 o β n = 10 o β n = 0 o β n = +10 o β n = +20 o β n = +30 o - (e) β n = 30 o β n = 20 o β n = 10 o β n = 0 o β n = +10 o β n = +20 o β n = +30 o (f) Figure 22. (cont.) Report 526 Cruciform model rudder effectiveness; δ r =+10 : (e) starboard sternplane, inner row, and (f) starboard sternplane, outer row. 42 DRDC Atlantic TM

54 β n = 30 o β n = 20 o β n = 10 o β n = 0 o β n = +10 o β n = +20 o β n = +30 o - (a) β n = 30 o β n = 20 o β n = 10 o β n = 0 o β n = +10 o β n = +20 o β n = +30 o (b) Figure 23. Report 526 Cruciform model rudder effectiveness; δ r = 10 : (a) upper rudder, inner row, and (b) upper rudder, outer row (continued). DRDC Atlantic TM

55 -2.5 β n = 30 o β n = 20 o β n = 10 o β n = 0 o β n = +10 o β n = +20 o β n = +30 o - (c) β n = 30 o β n = 20 o β n = 10 o β n = 0 o β n = +10 o β n = +20 o β n = +30 o - (d) Figure 23. (cont.) Report 526 Cruciform model rudder effectiveness; δ r = 10 : (c) lower rudder, inner row, and (d) lower rudder, outer row (continued). 44 DRDC Atlantic TM

56 - β n = 30 o β n = 20 o β n = 10 o β n = 0 o β n = +10 o β n = +20 o β n = +30 o (e) β n = 30 o β n = 20 o β n = 10 o β n = 0 o β n = +10 o β n = +20 o β n = +30 o (f) Figure 23. (cont.) Report 526 Cruciform model rudder effectiveness; δ r = 10 : (e) starboard sternplane, inner row, and (f) starboard sternplane, outer row. DRDC Atlantic TM

57 β n = 30 o β n = 20 o β n = 10 o β n = 0 o β n = +10 o β n = +20 o β n = +30 o - (a) β n = 30 o β n = 20 o β n = 10 o β n = 0 o β n = +10 o β n = +20 o β n = +30 o - (b) Figure 24. Report 526 Cruciform model rudder effectiveness; δ r = 20 : (a) upper rudder, inner row, and (b) upper rudder, outer row (continued). 46 DRDC Atlantic TM

58 -2.5 β n = 30 o β n = 20 o β n = 10 o β n = 0 o β n = +10 o β n = +20 o β n = +30 o - (c) β n = 30 o β n = 20 o β n = 10 o β n = 0 o β n = +10 o β n = +20 o β n = +30 o - (d) Figure 24. (cont.) Report 526 Cruciform model rudder effectiveness; δ r = 20 : (c) lower rudder, inner row, and (d) lower rudder, outer row (continued). DRDC Atlantic TM

59 - β n = 30 o β n = 20 o β n = 10 o β n = 0 o β n = +10 o β n = +20 o β n = +30 o (e) β n = 30 o β n = 20 o β n = 10 o β n = 0 o β n = +10 o β n = +20 o β n = +30 o (f) Figure 24. (cont.) Report 526 Cruciform model rudder effectiveness; δ r = 20 : (e) starboard sternplane, inner row, and (f) starboard sternplane, outer row. 48 DRDC Atlantic TM

60 β n = 30 o β n = 20 o β n = 10 o β n = 0 o β n = +10 o β n = +20 o β n = +30 o - (a) β n = 30 o β n = 20 o β n = 10 o β n = 0 o β n = +10 o β n = +20 o β n = +30 o - (b) Figure 25. Report 526 Cruciform model rudder effectiveness; δ r = 30 : (a) upper rudder, inner row, and (b) upper rudder, outer row (continued). DRDC Atlantic TM

61 -2.5 β n = 30 o β n = 20 o β n = 10 o β n = 0 o β n = +10 o β n = +20 o β n = +30 o - (c) β n = 30 o β n = 20 o β n = 10 o β n = 0 o β n = +10 o β n = +20 o β n = +30 o - (d) Figure 25. (cont.) Report 526 Cruciform model rudder effectiveness; δ r = 30 : (c) lower rudder, inner row, and (d) lower rudder, outer row (continued). 50 DRDC Atlantic TM

62 - β n = 30 o β n = 20 o β n = 10 o β n = 0 o β n = +10 o β n = +20 o β n = +30 o (e) β n = 30 o β n = 20 o β n = 10 o β n = 0 o β n = +10 o β n = +20 o β n = +30 o (f) Figure 25. (cont.) Report 526 Cruciform model rudder effectiveness; δ r = 30 : (e) starboard sternplane, inner row, and (f) starboard sternplane, outer row. DRDC Atlantic TM

63 1.5 δ r = +10 o δ r = 0 o δ r = 10 o δ r = 20 o δ r = 30 o C ζ - (a) β (deg.) 1.5 δ r = +10 o δ r = 0 o δ r = 10 o δ r = 20 o δ r = 30 o C ζ - (b) β (deg.) Figure 26. Report 526 Cruciform model rudder effectiveness, integrated pressures: (a) upper rudder, inner row, and (b) upper rudder, outer row (continued). 52 DRDC Atlantic TM

64 1.5 δ r = +10 o δ r = 0 o δ r = 10 o δ r = 20 o δ r = 30 o C ζ - (c) β (deg.) 1.5 δ r = +10 o δ r = 0 o δ r = 10 o δ r = 20 o δ r = 30 o C ζ - (d) β (deg.) Figure 26. (cont.) Report 526 Cruciform model rudder effectiveness, integrated pressures: (c) lower rudder, inner row, and (d) lower rudder, outer row (continued). DRDC Atlantic TM

65 δ r = +10 o δ r = 0 o δ r = 10 o δ r = 20 o δ r = 30 o C ζ (e) β (deg.) δ r = +10 o δ r = 0 o δ r = 10 o δ r = 20 o δ r = 30 o C ζ (f) β (deg.) Figure 26. (cont.) Report 526 Cruciform model rudder effectiveness, integrated pressures: (e) starboard sternplane, inner row, and (f) starboard sternplane, outer row. 54 DRDC Atlantic TM

66 β n = 30 o β n = 20 o β n = 10 o β n = 0 o β n = +10 o β n = +20 o β n = +30 o - (a) β n = 30 o β n = 20 o β n = 10 o β n = 0 o β n = +10 o β n = +20 o β n = +30 o - (b) Figure 27. Report 526 Cruciform model sternplane shadowing; δ s =+10 : (a) upper rudder, inner row, and (b) upper rudder, outer row (continued). DRDC Atlantic TM

67 -2.5 β n = 30 o β n = 20 o β n = 10 o β n = 0 o β n = +10 o β n = +20 o β n = +30 o - (c) β n = 30 o β n = 20 o β n = 10 o β n = 0 o β n = +10 o β n = +20 o β n = +30 o - (d) Figure 27. (cont.) Report 526 Cruciform model sternplane shadowing; δ s =+10 : (c) lower rudder, inner row, and (d) lower rudder, outer row (continued). 56 DRDC Atlantic TM