Control- Oriented Model of a Hypersonic Vehicle (MASTRIM) - Containing an Integrated, Advanced Propulsion Sub- Model (MASIV)

Transcription

1 Control- Oriented Model of a Hypersonic Vehicle (MASTRIM) - Containing an Integrated, Advanced Propulsion Sub- Model (MASIV) Jim Driscoll, Sean Torrez, Derek Dalle University of Michigan, Michael Bolender, Jonathan Muse, AFRL September

2 Outline A. MoNvaNon B. Results prior to last year C. Results for last year D. Next year s plans 2

3 A. MoNvaNon Develop an improved control- oriented model by significantly modifying Doman- Bolender model - hypersonic vehicle (MASTRIM) with integrated propulsion (MASIV) - compute lid, drag, thrust, moments in 1 sec on PC using ROMs - including realisic shock interacions in the inlet, - combustor finite rate chemistry, 3- D mixing - nozzle expansion waves to compute lower edge shear layer - add operability limits: ram- scram, unstart, flame- out 3

4 B. MoNvaNon Ascent trajectory of MAX- 1 trimmed vehicle 1. OpImizaIon study - how to minimize fuel? 2. MDO study opimize geometry (surrogate vs. collocaion) 3. Delivered to MIT - linearized A, B matrices, poles and zeros Operability Limits 4. When does ram- scram occur? 5. How much do forces jump at ram- scram? controllability? 6. When does unstart occur? 7. Can a befer trajectory avoid unstart? Generic hypersonic vehicle geometry (GHV, HiFIRE6) 8. Add 3- D shock interacions to inlet (3- D Riemann problem) 9. Add ethylene fuel lookup tables 4

5 MoNvaNon A Reduced Order Model (ROM) is required Suppose vehicle ascends along a constant dynamic pressure path We ask: when does ram- scram transiion occur? AlItude (km) acceleraion q = 0.6 atm 0.8 atm 1.0 atm MAX- 1 Computed ram- scram transiion boundaries Flight Mach Number To generate this plot: lid, drag, thrust, moments were computed 1500 Imes = (guess 15 AoA s to trim) X 5 (q values ) X 20 alitude values /curve 5

6 MoNvaNon ROM is best when thousands of force computaions are needed when opimizing the trajectory when generaing operaing maps for geometry opimizaion (MDO) ROM provides understanding of Operability Limits Unstart Margin - understand what factors help or hurt Ram- scram transiion - esimate large jump in forces Engine Flameout - need finite rate chemistry ROM is useful for a first look at the design space First idenify a small number of problem cases Understand what the problem is Run high fidelity CFD just for those cases 6

7 MoNvaNon: Operability Limits when does unstart occur? Unstart Margin = L 1 / L 2 L 1 = distance between leading edge of shock train and entrance to isolator L 2 = total length of isolator L 2 L 1 1. First must properly compute the thermally- choked (ram) case 2. Then MASIV predicts isolator back pressure (p back ) 3. Length of shock train then computed from experimental relaion (L 2 L 1 ) / H = funcion (p back / p inlet ) 7

8 MASIV tells us one way to avoid unstart! For a short isolator, MASTRIM shows that as you accelerate too fast (2 m/s 2 ) à you unstart before you reach ram- scram! Unstart Margin MAX- 1 ß unstart Flight Mach Number MASIV predicts the proper acceleraion path = lower ER path à reduce acceleraion to 1 m/s 2 for the predicted Ime period 8

9 MoNvaNon: Operability Limits = Unstart, Flameout, Ram- Scram Issues AlItude (h) insufficient mixing flame out (low Re) at low pressure insufficient lid, insufficient air flow to trim ram - scram engine unstart thermal limit of wall cooling Flight Mach Number M 9

10 B. Results Prior to Last Year 1. MASTRIM - Developed a 6- DOF Flight Dynamics Model of a Hypersonic Vehicle - based on Doman- Bolender trim code 2. Completed Propulsion/Vehicle integranon a. SAMURI - reduced order inlet & nozzle code addedà realisic inlet losses from muliple shock/expansion interacions. rapidly computes lower edge of exhaust plume b. MASIV - reduced order code for combustor method: lookup tables from high fidelity 3- D combusion, 3- D mixing added: finite- rate chemistry of hydrogen and ethylene fuel, gas dissociaion losses 3. Operability Limits - began methodology - ram- scram transiion, engine unstart, flame out at low pressure 10

11 B. Prior to last year (con t) 4. Published three examples: a) Level Flight Generic X- 43, Mach 8 b) Ascent OperaIng maps (δ CE, α, ER) vs. (M, h) c) Turn Poles, zeros, Ime to double amplitude 5. Disseminated the MASTRIM code Delivered MASTRIM to AFRL Demos to AFRL Air Vehicles and Propulsion Boeing (Bowcuf) HunIngton Beach March 11 NASA AMES (Soloway) Ohio State Demos at MIT and NASA Glenn are planned Michael Smart HyTASP Conference 6. ValidaNon tests vs. high- fidelity 3- D CFD & some experiments (6-10%) reduced run Ime to ~ 1 sec 11

12 Developed a 6- DOF Flight Dynamics Model MASTRIM control parameters: 1. δ CE elevon combined deflecion angle 2. δ ER equivalence raio change 3. Δx c cowl lateral translaion distance 4. Δy c cowl transverse translaion distance 5. Δθ c cowl flap angle 6. ε FUEL fracion of fuel injected at locaion 2 for a turning trajectory: 7. δ DE elevon differenial deflecion angle 8. δ CR rudder combined deflecion angle 9. δ DR rudder differenial deflecion angle Trims the vehicle Computes poles, zeros, Ime to double amplitude Δy c Δx c 12

13 Prior to Last Year SAMURI inlet ROM Track discrete waves, no CFD grid used Shocks: Expansions: exact 2- D oblique shock relaions with real gas properies discreize coninuous fan into 2-4 waves Wave interacions: exact Riemann jump condiions Boundary layers: displace wall by displacement thickness M oo = 10, α = 0, q = 2040 lbf/d 2 inlet losses: PRF = (stagnaion) pressure recovery factor ~ 60% inlet compression raio: p 2 /p = % error in our ROM compared to CFD++ for stagnaion pressure raio Dalle, J. of Propul. &Power,

14 Prior to last year: for nozzle, SAMURI predicts lower edge Riemann solver - interacion of many expansion waves engine flow Plume lower edge Dalle, sub. to J. of Propul.& Power,

15 MASIV Reduced Order Model of Combustor bow internal isolator const area diverging external shock inlet burner burner nozzle e Pre- computed lookup tables of finite- rate chemistry of jet- in- cross flow mixing 15 species, 22 reacions ethylene or hydrogen fuel Fuel can be added anywhere Area is variable Wall fricion, heat transfer Real gas properies Torrez, J. of Propul. & Power,

16 Prior to last year flight dynamics of climbing flight acceleraion from Mach 7 to Mach 11, constant q & mass flow air trajectory minimizes total fuel consumpion stable to unstable transiion at Mach 9.5 due to increased α 16

17 PublicaNons, Awards Sean Torrez won AIAA Airbreathing Propulsion Graduate Student Award at San Diego AIAA JPC Prior to last year = one journal paper, 12 AIAA conference papers Reduced- Order Modeling Inlets, J. of Propul. &Power, Last year = 4 journal papers, 5 AIAA conference papers 1. Reduced Order Modeling Scramjet, J. of Propul. & Power, Reduced Order Modeling...Nozzles, J. of Propul. & Power, Ram- Scram TransiIon J. of Propul. & Power, Minimum- Fuel Ascent Using Surrogate OpImizaIon, submifed to JSR, Ram- Scram TransiIon on Ascent Trajectory, to be submifed, Performance Analysis of Variable- Geometry Scramjet Inlets AIAA Paper Design of Flowpaths, AIAA Turn Performance of a.hypersonic Vehicle, AIAA Hypersonic Vehicle Flight Dynamics, AIAA Flight Envelope CalculaIons of a Hypersonic Vehicle AIAA Paper Uncertainty PropagaIon in Integrated Airframe- Propulsion Systems, AIAA

18 C. Last Year - Results Ascent trajectory of MAX- 1 trimmed vehicle 1. OpImizaIon study - how to minimize fuel? 2. MDO study opimize geometry (surrogate vs. collocaion) 3. Delivered to MIT - linearized A, B matrices, poles and zeros Operability Limits 4. When does ram- scram occur? 5. How much do forces jump at ram- scram? controllability? 6. When does unstart occur? 7. Can a befer trajectory avoid unstart? Generic hypersonic vehicle geometry (GHV, HiFIRE6) 8. Add 3- D shock interacions to inlet (3- D Riemann problem) 9. Add ethylene fuel lookup tables 18

19 C. Last Year: Ascent trajectory opnmizanon - minimize fuel surrogate method: q = constant compute operaing maps of: (ER,, α, δ CE, ) = fcn (M, ) minimum fuel trajectory: q = 1 atm. acceleraion varies as: ER varies as: 24 km Altitude 32 km 24 km Altitude 32 km Dalle, Torrez, Driscoll, Bolender, Bowcuf, sub. to JSR 19

20 Last Year: MDO study - opnmize geometry Minimize fuel along a constant q = 1 atm. path Study #1: vary locaion of fuel injecion, angle of wall divergence locaion of wall divergence Torrez, Dalle, Driscoll, AIAA

21 Last Year: MDO study - opnmize geometry Dalle, Torrez, Driscoll, AIAA Study #2: Displace cowl verically (Δy) change compression raio Displace cowl horizontally (Δx) change spillage, mass flow Rotate cowl lip (Δθ) - shid shock interacion locaions What geometry provides best compression? Lowest fuel required? 21

22 Result for opnmizanon study: opnmize flowpath Performance Analysis of Variable- Geometry Scramjet Inlets AIAA Paper Design of Dual- Mode Engine Flowpaths, AIAA Thrust (normalized) upstream fueling Varied: δ x cowl δ y cowl α δ Θ flap M Maximized: Inlet recovery Factor (p 02 / p 01 ) p 3 in 10 5 Pa downstream fueling Varied: fuel injector locaion Maximized: thrust Design of Dual- Mode Engine Flowpaths, AIAA

23 Last year: Operability Limits: added ram- scram transinon Where is the thermal choking locaion? How to solve ODEs near the singular point? L Hospital s Rule: choking is where: area change (given) ~ heat added by combusion Torrez, S., AIAA

24 Last Year: Operability Limits when does Ram- Scram occur? AlItude (km) acceleraion q = 0.6 atm 0.8 atm 1.0 atm Computed ram- scram transiion boundaries MAX- 1 Flight Mach Number If you require larger acceleraion you need larger ER - stay thermally choked longer - so: larger Flight Mach Number at ram- scram transiion 24

25 Last Year: DerivaNves of performance curves are disconnnuous - at ram- scram, affecing controllability ram- scram boundary vehicle altitude (km) ram scram Thrust in kn flight Mach number M Torrez, S., AIAA

26 Last Year how large are the sudden jumps in forces at ram- scram? a challenge to the control system before ram- scram wall pressure (atm) before ader ram- scram x/h ader x/h inlet shocks jump during ram- scram wall pressure jumps down during ram- scram 26

27 Last Year: Operability Limits when does unstart occur? Unstart Margin = L 1 / L 2 L 1 = distance between leading edge of shock train and entrance to isolator L 2 = total length of isolator L 2 L 1 1. First must properly compute the thermally- choked (ram) case 2. Then MASIV predicts isolator back pressure (p back ) 3. Length of shock train then computed from experimental relaion (L 2 L 1 ) / H = funcion (p back / p inlet ) 27

28 MASIV tells us one way to avoid unstart! For a short isolator, MASTRIM shows that as you accelerate too fast (2 m/s 2 ) à you unstart before you reach ram- scram! Unstart Margin MAX- 1 ß unstart Flight Mach Number MASIV predicts the proper acceleraion path = lower ER path à reduce acceleraion to 1 m/s 2 for the predicted Ime period 28

29 Last year: added the flame- out limit Our finite- rate chemistry goes out if : combustor gas pressure or temperature is too low combustor gas velocity is too large (scalar dissipaion rate) inlet provides insufficient compression raio lookup tables: chemical reacion rate = funcion (dissipaion rate) 29

30 D. Next Year 1. Add Generic Hypersonic Vehicle: 2. Add 3- D inlet: 3- D Riemann wave interacions, inward- turning add Tyler s AFRL Vehicle Model Generator 3. Ethylene fuel: run GHV on ethylene fuel, speed up code 4. Uncertainty: apply uncertainty analysis to compute data needed by Anu s adapive control model 5. IntegraNon of Cesnik s aero thermo elasic model with: MASTRIM trim code, external forces MASIV propulsion code 30

31 D. Next Year (connnued) 6. InteracNon: with Anu Annaswamy s AcIve- AdapIve Control Laboratory at MIT to couple MASTRIM to her adapive control model 7. OpNmizaNon of more of the control variables (cowl displacement, elevon size, fuel type) 8. Operability limits - flame out limits 9. ValidaNon: determine uncertainty of our unstart, ram- scram predicions 10. MDO: opimize inlet panels, elevon size, combustor length for GHV 31

32 Next Year - Provide Uncertainty - to MIT for adapnve control Adaptive Control of Hypersonic Vehicles in the Presence of Thrust and Actuator Uncertainties, T. Gibson, Anu Annaswamy, AIAA Uncertainty in Analysis of Integrated Airframe-Propulsion for Hypersonic Vehicles N. Lamorte, D. Dalle, S. Torrez, J. Driscoll, AIAA Λ = effect of thrust uncertainies on the B matrix R s = rectangular saturaion funcion = u i (if u i < u max ) d = disturbance term u = control input δ thrust, δ elevon 32

33 Next Year: 3- D Inlet - wave interacnons for GHV Compound Compressible Flow and Streamline Tracing 3- D inlet Discrete stream tubes; Shapiro influence coefficients; Enforce cons. mass, mom, energy + surface tracing of 3- D shocks Compound Compressible Flow for Hypersonic Inlets, Mark Lewis, AIAA D Analysis of Inward-Turning Inlets, Malo-Molina, Gaitonde, AIAA J. 48, 2010 Hypersonic Inlet Rectangular to Ellipical, M. Smart, C. Trexler, JPP

34 IntegraNon with Cesnik s aero thermo elasncity model - Begin with X- 43- like MAX- 1 vehicle - Revisit Doman- Bolender problem effect of longitudinal bending on inlet shocks, spillage, loss of thrust - Add more complex geometry and thermo elasicity model - Add muliple shock interacions that were omifed in Doman- Bolender - Consider intense heat transfer where bow shock reflects from engine cowl 34

35 Next year: compute controllability AlItude (h) ram scram* engine unstart gas density too low for elevons structural excessive forces on elevons Flight Mach Number M Metric: Time- to- double amplitude, which varies along trajectory vehicle altitude (km) *At ram- scram limit: thermal choking b.c. suddenly disappears, Sudden change in wall pressures, forces, moments DerivaIves of thrust performance curves are disconinuous ram scram Thrust in kn flight Mach number M 35

36 Flight Dynamics of a High Speed Turn Trajectory increasing the Mach number shortens the period of each mode Pole Time to Double

37 Long term impact MASTRIM is a validated flight dynamics plahorm upon which to build an adapnve control law Anu Annaswamy (MIT): adapive control methods to avoid unstart, flame out, and issues during ram- scram transiion - needs a validated flight dynamics model - needs uncertainty analysis - flight dynamics model must be sufficiently fast, robust, and have sufficient control variables - fundamental aspect of our model is important we can explain why the control system adapts in a certain way 37

38 Payoffs to the Air Force Research addresses important component of control design and analysis development Novel modeling approaches to support G&C design and analysis beginning in the vehicle conceptual design phase State- of- the art techniques in reduced- order and first- principles modeling Codes have been transiioned to NASA AMES, AFRL, Boeing, and Raytheon 38