Measurements of Oscillatory Derivatives at Mach Numbers up to 2.6 on a Model of a Supersonic Transport Design Study (Bristol Type 198)

Transcription

1 CP No 815 MINISTRY OF AVIATION AERONAUTICAL RESEARCH COUNCIL CURRENT PAPERS - ; Measurements of Oscillatory Derivatives at Mach Numbers up to 26 on a Model of a Supersonic Transport Design Study (Bristol Type 198) by I S Thompson, BA and R A fail, &SC *,- l k e LONDON: HER MAJESTY S STATIONERY OFFICE 1965 PRICE 9s Od NET

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3 UDC No 533e613~5 : 5336~434 : CP No815 November, 1964 IGFASREMENTS OF OSCILLATORY DERIVATIVES AT MACH NUMBERS UP TO 26 ON A MODEL OF A SUPERSONIC TRANSPORT DESIGN 2mJDY (BRISTOL TIE 198) by J' S Thompson, B,A R A Fail, BSc This Report gives results of oscillatory derivative measurements on a model of a Bristol supersonic transport design type 198 The tests were made in the 8 ft by 8 ft supersonic wind tunnel at R,A,E Bedford at six Nach numbers from 2 to 26, and the results include most of the longitudinal and lateral derivatives with respect to angular motion in pitch, yaw, and roll, The method of test has been described in a previous reporti, but some further details are given in this Report Replaces RAE Tech Report No ARC Y-e

4 2 4 INTROIXJCTION 2 METHOD OF TEST 3 DESCRIPTION OF MQDEL 4 TEST CONDITIONS 5 PRESENT~ION OF RESULTS 6 DISCUSSION 7 FURTHERDEVELCWvENTS 8 CONCLUSIONS Appendix A Details of roll spring unit COWTENTS Appendix B Corrections for variations in mechanical stiffness Table 1 Table 2 Model particulars Test conditions Table 3 Summary of results - longitudinal derivatives Table 4 Sumnary of results - lateral derivatives Table 5 Numerical example - roll-yaw test Notation References Illustrations Detachable abstract cards Page IO II Figures I-4

5 1 INTRODUCTION A method for measuring oscillatory derivatives in the 8 ft supersonic wind tunnel at RAE Bedford has been described in Ref?, and the present Report gives the results of tests with this rig on a model of the Bristol type 198 supersonic transport design study Measurements have been made of longitudinal and lateral derivatives, and include tests with a new roll spring unit, Two appendices give some further details of experimental technique arising from these tests, 2 ME!THOD OF TEST For these tests the model was mounted on a spring unit on the end of a sting, and excited at constant amplitude by means of a moving coil vibration generator The general arrangement for yaw and sideslip tests is shown diagrammatically in Fig?, in which the spring unit is replaced by its equivalent pivot and spring The system is treated as having tvfo degrees of freedom, and full details are given in Ref1 A new roll spring unit was used for some of the present tests, and details of this are given in Appendix A This unit was intended to have only one degree of freedom, but in practice it was found to have appreciable flexibility in yaw, so that the system had to be treated as having two degrees of freedom, and measurements were made in the yawing mode at about 12 cps as well as in the rolling mode at 1 cps Excitation of the yawing oscillations occurred only because of the inertia coupling (Izx) between the two modes There was also a certain amount of oscillation in sideslip, but there was no provision for exciting or measuring a third (sideslip) mode, Because of this sideslip motion, no cross derivatives could be measured satisfactorily, and reliable results were obtained only for the direct derivatives 4$ and 4$ At each test condition the static forces and moments were measured on the appropriate spring units (with ordinary wire resistance strain gauges) for & range of incidence and yaw so that the static derivatives could be obtained from the slopes of the curves 3 DE~S'XUFTION OF MODEL The model, shown in Fig2, represented a supersonic transport design study undertaken by Bristol Aircraft Ltd (Type 198) The wing camber was designed by linear theory for M = 22, C % = 2, and a centre of pressure

6 4 shift of 15 8 at CL = 1 Leading dimensions and details of the model are given in Table 1 No engine nacelles were fitted In order to provide sufficient clearance between the sting and the inside of the model, the conical sting shield had to be four inches diameter at the tail, thus causing considerable distortion of the rear body The fin was detachable and the lateral tests were repeated without the spring the fin The model was made of fibre-glass with a steel insert for mounting on unit 4 TEST CONDITIONS Details of the test conditions are given in Table 2, Since there seems to be some doubt about the desirability of fixing transition in tests of this kind, no arrangements were made to fix transition in these tests At Mach numbers of 8 and above, the incidence was limited to a maximum of' 8' on account of the stresses in the spring units produced by the steady aerodynamic loads on the model 5 PRESENTATION OF RESULTS The results are presented in Figs3 to 34, Tables 3 and 4 serving as an index All of the results are referred to a reference axis at 52 Co The ncn-&ension& coefficients are defined under "Notation" below The static derivatives were obtained from the slopes of the curves of Figs35 to 39; static pitching moment, normal force and rolling moment were measured over the same range of incidence as in the dynamic tests, but yawing moment and side force were measured only at zero incidence Certain derivatives could not be measured satisfactorily; these are also listed in the tables, with appropriate comments, but the results are not presented Generally the results are plotted against the normal force coefficient, C s, so that it has not been necessary to apply any corrections to incidence In the case of the static tests, however, the values of the incidence and yaw have been corre,cted for deflections of the sting and spring unit so that the slopes of the curves are directly comparable with the dynamic results The question of the reliability and accuracy of this method of testing is fully discussed in Section 5 of Refl

7 5 6 DISCUSSION \ The results show no unexpected large variations and generally no large irregularities Comments on some features of the results are given belcw Under certain conditions some of the derivatives decrease sharply near or just above zero lift, possibly because the flow is then attached!&@a1 examples of this are seen in the case of ze at low speed (Fig3) at Sp3edS up to M = 14 (Fig36) Except in the tests at M = 2, the static values of m are about 1 more positive than the dynamic values (Fig5) The same effect was observed in tests of a cambered ogee modefl It is still considered doubtful whether this effect is genuine, although the differences are rather too large to be attributed to known experimental errors and no other explanation has been found It is interesting to note that most of the variations in n$ and n$ (Figs16 and 19) with fin on are repeated with fin off, thus leading to smooth curves for the fin contributions and tending to give confidence in the reliability of the measurements The fin contribution to n$ (Fig22) is almost constant at subsonic speeds but decreases with increasing incidence at supersonic speeds The fin contribution to nt (Pig24) is larger at subsonic speeds than at speeds of M = 18 and above, while at M = 14 the lower value is obtained at low incidences and the higher value at high incidences The derivatives 4@ referred to sting axes must be equal to -4$ tan a (See Ref?, Appendix IV) The results, shown in Fig34, are therefore of little aerodynamic interest, but give another check of the reliability of the measurements 7 FURTHERDEVELOPMENTS Two further developments in the technique should remove some of the difficulties referred to in this Report k A new spring unit has now been made, which is designed to have suitable flexibilities in yaw, sideslip, and roll, with provision for exciting and measuring all three motions This should avoid the limitations of the roll spring unit (para2) New measuring equipment, designed for automatic recording, has also been provided, which is expected to improve the accuracy of measuring small phase angles in the presence of noise (see Tables 3 and 4)

8 6 The latest form of the equipment will be used for tests on a model of the Concord 8 CONCLUSIONS Measurements have been made of most of the derivatives with respect to angular motion in pitch, yaw,and roll, and the results show no unexpected large variations The new roll spring unit has been found to have certain limitations and it seems that the best way to obtain a complete set of lateral derivatives will be to use a combined spring unit with facilities for measurements in yaw, sideslip, and roll, Such a unit has now been made

9 :~~~~~~~~~~~~~I;~~~~RO~ SPRING UNIT, I The roll spring~unit'j which-was used for the first time in these tests, is illustrated in F&g&Q- -Each of the four cross s@lngs which locate the ; rolling ~a%is:~has San- e~~~~~~c$iver:leng'th (perpendictiar I% the axis) of 15 inches, a width (paraxlel;-to- thee *axis) of 2iO inches, and -a thickness of 4 inches * The two Long&tLCiinaI~~s%iffeners are IO inches longxwith a section 517 inches by 285 inches, chamfered off to a 9' angle on the inside, as shown in a sketch The whole unit is machined out of one piece of steel The exciting roi3ing moment is applied by twisting the driving rod The linkage between the vibration generator and the rear end of the driving rod gives an effective radius arm of about 27 inches

10 Appendix B, CORRECTIONS FOR VARIATIONS IN MEXXANICAL STIFFNESS Laboratory tests on the spring units have shown that in certain cases the mechanical stiffness of the unit is affected by the application of steady loads Thus in tunnel tests the steady aerodynamic pitching moment and normal force can produce changes in the mechanical stiffness which will cause errors in the aerodynamic derivatives deduced from the difference between wind-on and wind-off values Corrections for these effects have been obtained from laboratory tests and applied to the tunnel results on this model as follows:- Yaw spring unit Roll spring unit Correction to Q: 1 ICm + 5 Cz) Correction to ecp: -214 Cz There are also changes in mechanical cross-stiffness of the pitch spring unit which are apparently due to variations in the sting support system and cannot be correlated with steady aerodynamic loads There are significant differences between the wind-on and wind-off values of hk, which cannot represent an aerodynamic Mz, since this derivative should be negligibly small, The differences are presumably due to changes in the mechanical Mz, and in fact day-to-day variations of the same order of magnitude* occur in the wind-off measurements of Mz and Ze (These two mechanical cross-stiffnesses are the same) The effect of these variations on the measurements of the aerodynamic Z has been eliminated by assuming that the aerodynamic Mz is zero, and writing Aerodynamic Ze = (Ze - Ms) wind-on iilstead of (z,> nind-on 4%) wind-off + ) 1 lb, representing about + 5 in mz and z8 at hl = 14

11 9 Table 1 KDEL PARTICULARS (BRISTOL TYPE 198) Model fill Scale' Wing: Centre line chord co -366 ft 111 ft &an b 234 ft 84 ft Area S 3783 w ft 4875 sq f't Aerodynamic mean chord B 25 ft 736 ft Overall length 5237 f't 184 ft Position of reference axis forward of TE ( ie 52 Co from apex) 448 ft 532 ft Sting axis inclined 21' nose up relative io OH datum II * II I1 5' nose down I',"wing root chord I I *Based on model scaie F l/359

12 IO Table 2 TEST CONDITIONS Speed (ft/sec) 24 &iach number (2) r $pv2 (lb/ft?) 68 26, I t Range of incidence to 2 ' to 8O (in most cases) y L= ace [Pitch I LHeave v = & f Yaw 21 o ,26 2v,Sideslip (no aerodynamic results) Reynolds number (based on co) I,,5 x IO6 APPROXIMUE VALU3S 3 OSCILLATION FREQUENCIES AND AMPLITUDES Type of test I Motion 1 Frequency Amplitude!(cycles/sec) (peak) Pitch-heave Pitch 7 to 77 + I Heave in, i Yaw-sideslip Roll-yaw Yaw Sideslip Roll I IO4 Yaw p2 r

13 11 Table 3 ftxwmry OFRESULTS - LONGITUDINAL DERIVATNES I m = I I Satisfactory Satisf&tory 8 Figs4 and 5 Figs 3 and 6 (Fig13) (Fig14) z * 2 Satisfactory M = 2 Only r?l 8 Figs7 and 8 Fig1 g / (Fig-t2) See note A 2 *' X Used only to Too small to 1 rz correct 2 measure* 24 See Appendix 2 *l-l 9 i I I p-r Less reliable Satisfactory than &II Figs9 and 11 (Fig 14) I Notes : A -Determination of this derivative involved the measurement of small phase angles in the presence of noise, which could not be done satisfactorily with the available equipment The figure numbers in brackets refer to figures showing the variation of the derivatives with Mach number at one or two constant values of Cz

14 12 Table 4 SUldMRY OF RESULTS - LATERAL DERIVATNES I Y I n I e Satisfactory Satisfactory Satisfactory 9 Fi s15 and 16 Figs17 and 2 Figs27 and 28 7 Fig25) (Fig26), (Fig 31) Satisfactory Incomplete Jr FigT;li ;$ 19 Fig21 1 i, See note A I t i 2 *, 2?j 5 '- t Satisfactory Fig29 (Fig32) ' Too small to Too small to Too small to I measure measure measure Too small to Too small to Less reliable than measure measure etf See note B See note B See note B Roughly equal to QI tan a ] Fig3 (Fig33) Less reliable in yaw-sideslip tests Unsatisfactory See note A than Notes :- A - Determination of these derivatives involved the measurement of small phase angles in the presence of noise, which could not be done satisfactorily with the available equipment B These derivatives could not be measured pro erly because no sideslip measurements were made (see Appendix A P The figure numbers given in brackets refer to figures showing the variation of the derivatives with hkch number at one or two constant values of Cz

15 93 Table 5 NUMERICAL EXAhPLE - ROLL-YA17 TEST Constants IXX 12X Measurements a Niach no v &pv2 Rolling $Jh WV n mode Yawing mode sklgs-ft* 126 slugs-ft* -73 degrees ft/sec $b/ft2 lb-ft-set* cycles/set cp/jr WV lb-ft-set* 2 I 6/o * Oo47/9 n 1 cycles/set ~129, Wind-off! vi&-on -o65/o"* 156/9 126 Derivatives obtained from above measure #lb-ft!lb-ft I I W \ Ib-ft-set i -19 w [lb-ft-see [-126]* I /o * ooo65/yo" /o * 127/Y 11,925 ents [-3991" * In these cases no measurements could be made of the small phase angles, and so the values of LQ, are not reliable

16 Axes NOlW!L'ION --- All forces, moments, displacements, derivatives, and coefficients are referred to "sting axes", ie a system of earth axes fixed in the mean position of the oscillating model, A set of equations for conversion to other systems of axes is given in Appendix IV of Ref1 Displacements and velocities Forces and moments Y 9 z i 'p If Side force Normal force Rolling Pitching i moment moment Yawing moment sideslip heave roll pitch Yaw Y = & p v2 s cy z = & p v2 s c, L = 4P v2 sb ce x4 = SP v2 s co cm N = &P V2 Sb Cn Derivatives are denoted by suffices, e g Me = akr/a 6 = pitching moment due to pitch displacement Non-dimensional derivatives are denoted by small letters (eg mg); and have been obtained from the measured aerodynamic values as follows:- For me divide by PV2ko me p v SC,2 28 and y$ II p v2 s % PV *o n$, 4Q and -% II II p V2 S ($b) n$, 447 and 4@ II 19 p V S (&b)2 Yjr 11 II p V S (+b)

17 15 Other symbols b co 1xX 7 12X Le wing span wing centre-line chord roll moment of inertia of model roll-yaw product of inertia of model rolling moment excitation Mach number (used where no confusion with pitching moment can arise) oscillation frequency wing area wind velocity angle of incidence angle of sideslip fin contribution to a derivative frequency parameter w co/v longitudinal o b/2v lateral P air density circular frequency (= 2m)

18 REFEZENCE J& Author Title, etc 1 J S, Thompson Oscillatory-derivative measurements on sting-mounted R, A, Fail wind-tunnel models: method of test and results for pitch and yaw on a cambered ogee wing at Mach numbers up to 26 AR*C, R&M 3355, July 1962

19 , MODEL EXClr(ER \CONlCAL SHIELD DRIVING / ROD /l-l 1-iziz-l r- ----m- J - -_ _ AMPLIFIER -I t, I EXCITER CURRENT I ; r--a i I -4,r-l 1 -- PHASE i I---, METER COUNTER l i i I i d6clj FIG I SCHEMATIC ARRANGEMENT FOR YAW - SIDESLIP OSCILLATIONS

20 L-Y-Lo SCALE OF FEET STING -LEADING AXIS EDGE / OH DATUM WING APEX 3EFERENCE -- AXIS -- 4 I / I FIG 2 BRISTOL TYPE 198 MODEL

21 I6 -se - (STING AXES) I@2 I* % *, M = Oe2 % FIG3 CROSS DERIVATIVE,-& M---2 o-2 4 o-4 O-6 -c 2 *8 %I (STING AXES) - *4 M = O-2 -*6 - O I I, i / I 2 o-4 6 -c C z FIG4 STABILITY IN BITCH, me M5 2

22 l me (STING AXE$ -- 3 K & -O-IO DYNAMIC STATIC x A M = me ( STING AX& I -*12 I M = 2*2-14 -Oar8 L 1 --I CZ -l FIG5 STABILITY IN PITCH, m,

23 DYNAMIC STATIC 4 -%3 (STING AXES) I* O-8 4 %J ( STIN IG AXES) FIG6 CROSS DERIVATIVE,- se

24 O*lO -mh (STING AXES) I M = o-2 = 6, 94 o-2 f o*e *4 Cz 6 O-8, FIG 7 DAMPING IN PITCH, -m Mz2

25 16 1 = 2*6 *6-1 FIG 8 DAMPING IN PITCH, -ma

26 (ST1 NG 3% AXES) *6 FIG 9 DAMPING IN HEAVE, $2 M= (STING AXES) M = *2 ' -*2 *2 *4 O-6 8 -% FIG IO CROSS DERIVATIVE, -j& M=2

27 1*2 t % (STING AXES) I* --- *8 --- FIG11 DAtulPING IN HEAVE, - 3%

28 -mi, ( STING AXES) I -c*= 5 FIG I2 DAMPING IN PITCH; rnb VARIATION MWITH MACH NUMBER 2 3 me (STING AXES) -2 I 2 M FIG, 13 STABILITY IN PITCH, me VARIATION WITH MACH NUMBER

29 I* (STINt 'b AXES) *8 I M 2 3 FIG14 CROSS DERIVATIVE, - 3 VARIATION WITH MACH NUMBER

30 O-6 nv (ST1 N G AXES) a*4 FIN *2 M = * *6 FIN ON I I -o*oa -O-IO o-2 o-4 Cz *6 O-8 FIG IS STABILITY IN YAW, n,pm=o-2

31 a ( O*Ol % STING AXES; O-4 ; D- A- -o*o; - o*ol C 1 FIN ON I I I I FIG16 STABILITY IN YAW, n+

32 YV (STING AXES) FIN OFF M = 2 -*2 oa2 94 Oa6 Oa8 -% FIG 17 CROSS DERIVATIVE, y q M = O-2 - FIN FIN OFF -2 *2 O-4 -c *6 t FIG I8 DAMPING IN YAW, -n$ M =*2

33 J 4 I I fm = I l i3 \ FIG I9 DAMPING IN YAW, -nw

34 % (STING AXES) yw (STING AXES) I I ( I FIG 2 CROSS DERIVATIVE, y w

35 *3 W (STING AXES) O*Z ;: (STING y+ AXES) - I = 26 --d-w- FIG21 CROSS DERIVATIVE, yp

36 l --2 *v (STING AXES) I I -* 'Cz 1 FIG22 STABILITY IN YAW FIN CONTRIBUTION, A n 9

37 -n-j, ( STlNq AXES; O-3 Cz = o-5 w FIN ON - O-2 FIN OFF FIG23 DAMPING IN YAW, -n+ VARIATION WITH MACH NUMBER FIG24 DAMPING IN YAW FIN CONTRIBUTION, -An+

38 5 nv ( STING AXES C x --- l3-?!r /-- -+j--- I% \1 t \I I STATIC DYNAMIC FIN OFF -x-- - m- I FIN ON II FIG 25 STABILITY IN YAW, ne VARIATION WITH MACH NUMBER *2 yv ( STING AXE$ 15 Ai!- 1 + STATIC DYNAMIC i FIN ON -oq \ FIN OFF ex--- -Elx ---&, *5 I % \ \ I- w - x A5 Is 1 Elh l I 2 3 d=o FIG 26 CROSS DERIVATlVE,y~VARIATION WITH MACH NUMBER

39 O-3 I (STING h AXES) k I -a2 2 4 O-6 8 I - cz FIG 27 CROSS DERIVATIVE,+ M=*2

40 1 (STING e, AXES) *5 4 i5 f- c X ; STATI c DYNAMIC FIN ON FIN OFF -X--- a- l c FIG 28 CROSS DERIVATlVE, t),

41 I ] FIN ON 1 ) M = 2*6 FIN OFF I 3 6, FIN ON FIN OFF M= 262 FIN ON FIN OFF M= I*4 M= o *FIN ON FIN OFF -*2 O-2 I* FIG 29 CROSS DERIVATIVE f$

42 ( STING AXES; OIS -K 5 4 h x-- \ 9 h \ \ \ I /,KY / L( X ) M= *2 * \ M= I*8 f2 M = 2e2 ; 4=1*4 (=I*8 i M= 2*6 I= 2-2 IN ON X -----X fin OFF t1=2*6 -*2 o-2 o-4 Oe6 *8 I -cz FIG 3 DAMPING IN ROLL,-$,j

43 ( % STING AXE< O*I WITH MACH NUMbER FIN ON % (ST1 N G AXES) O-2 P, -A * t I I I I I I 2 FG 32 CROSS derwa+we, -e & ARumO; WITH MACH NUMBER 3 )O FIG33 DAMPLNC I bi -WITH ROLL, -44 VACATION M MACH NUMBER j ;

44 I I I \ x - is n L M = 2*2 + O IO 12 oc FIG 34 COMPARISON OF e$ AND t,,, tan d

45 3 -cz O-2 -I C C C FIG 35 STATIC NORMAL FORCE;CL

46 I- C )=- -2 b - Cm -O=Ok c- -4 o 4O 12 16O coo d FIG 36 STATIC PITCHING MOMENT, C,

47 I O*Ol Cn - Id O I C L c; )(- 91 C- *--x---r- --\ c- I -- T f I -2O -I O to 2* -13 FIG 3 7 STATIC YAWING MOMENT, C,

48 II CY I k FIN ON d= -- x --- FIN OPF fi a 4 -I O I" i -p?o FIG 38 STATIC SIDE FORCE, Cy

49 O*OOE - C4 t 3 - t 3- ( I- C )- C ) - I- L FlG39@) STATIC ROLLING MOMENT, C{

50 2 cc c r c FlG39(b) STATIC ROLLING MOMENT, Q

51 4 Ce O-2-2O -I O I (cl d= e + 2o FIG39(c) STATIC ROLLING MOMENT, Cf

52 FORWARD END YAW ACCELEROMETER (ATTACHED TO MODEL) FLEXURE SPRINGS ACCELEROMET ER DRIVING ROD NPICAL I SECTI ON (RIGIDLY ATTACHED TO FORWARD END OF SPRING UNIT) FIG 4 ROLL SPRING UNIT l

53 ARC CP No815 November, al315: Jm S, l-=q-n : R A Fail 533&oll5 MEAsuRMENT8W OSCIldATCRYDWIVATIVESATMACHNttfBERSDP M ~~~B?AMODELCFA -ctfunsportdesignsrddy (BRISTUL TYPE 198) ARC CP No815 November, AJn315: J S Thqpscn : R A Fail MUWEHEWSOF ~I~MWYDWfVATIVESAT~CH~~UPM ~~ONAMODELOFA SDPERSCNIClRANSPORTDESIGN~ (BRISTOL TYPE 1981 This Repart giws results of osoillatory Qrlvatfve mea muwmntsonamodel of a Bristol mwersonic transport deaigntypa 198 The tests -a~3 made in the8ftby8ftsupersonicwind~latrjl~bedlardataixpiach numbers mxa 2 to 26,and tbs results fnclu& most Or the longitudlnel and lateral deriwtives withrespect to arwlar motion in pltoh, yaw, and roll The method of test has been described ina previous report, but scme ruvther detailsare given lnthisrepox% This Report gloss nmlta derivative um8ummnte on a model or abristol ~~tper~olli~wans~~~rt design type isa The tests ~81-+3mada in thz 81tby8itmpersonicwi~t~latR~~e~ordatair~oh rnrmber~ rrtm 2 t 26, and tht3 ~sult8 intade m8t r thf3 mgmaml,ml lateral derivative8 vdthrespectto angularmotion inpitch,yaw,and roll Themethodof test hrsbean desoribed ina previou~mpor4i, but EEJIIE furtherdstailsam giwn inthi8report ARC CP Na815 November, la Jr S, Thompson R A Wll This Report gives results of oscillatory derivative maa 8kmment8 onamodsl Or abrlstolsupersontct~portdssigntyps 198 Ths ~~~~SWOI%IBS~O in the 8 rtby 8 tt imper8onlc windtunnelat RAE Bedfordat six%aoh numbers fr+xn 2 to 26, and the results include most of the longitudinal and late~lderivatlveswithrespectto angular motion in pitoh,yavr,and roll, The method of test has been described ina p-evious report, but some further detailsare given in this Report

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56 CP No 815 Crown Copyright 1965 Published by Han Mu~sn s SrATIONERY omcz To be purchased from York House Kingsway, London wc2 423 Oxford Street London w1 13~ Castle Street, Edinburgh 2 LO!4 St Mary Street, Cardiff 39 King Street, Manchester 2 5 Fairfax Street, Bristol 1 35 Smallbrook, Ringway, Birmingham 5 8 Chichester Street, Belfast 1 or through any bookseller CP No 815 SO CODE No