On the coupling of advanced modelling methods for big data generation on realistic aerodynamics flows

Size: px

Start display at page:

Download "On the coupling of advanced modelling methods for big data generation on realistic aerodynamics flows"

Phoebe Hines
5 years ago
Views:

1 On the coupling of advanced modelling methods for big data generation on realistic aerodynamics flows Pierre-Elie WEISS Applied Aerodynamics Department Missiles Hypersonic Launchers Unit Multiphysics and Unsteady Simulations for Aeronautical flows (MUSAF III) September 2016

2 Content 2

3 Context: Understand the side-loads generation Ariane 5 ECA launch on February 12 th 2009 (full launcher configuration) Ariane 5 ECA launch on August 14 th 2008 (zoom on launcher base) 3

4 Content Purpose What is the need in applied aerodynamics? What validation means for applied aerodynamics? Proposal: coupled numerical strategy ZIBC Ariane 5: A typical example of complexity Big data: the next step 4

5 Content Purpose What is the need in applied aerodynamics? What validation means for applied aerodynamics? Proposal: coupled numerical strategy ZIBC Ariane 5: A typical example of complexity Big data: the next step 5

6 Content Purpose Solving complex flows around realistic configurations in applied aerodynamics Complex flows: e.g. several mixing layers interacting with several recirculation bubbles with a wide range of characteristic frequencies Complex geometries in applied aerodynamics: assembly of simple bodies & many technological details 6

7 Timeline: ZDES studies of afterbody flows at ONERA : RANS to DES Buffeting 2005 flow control transonic Complex configurations Immersed Boundary Conditions ZDES Base flows simple geometry sub- and supersonic Ovalization flow control transonic Design faster still accurate - > PhD thesis > 20 communications > 10 high-ranking publications (JFM, POF, ) 7 level of validation for each simulation

8 Starting point of the present study Former studies evidenced : Buffeting phenomenon is related to a low frequency (St D =0.2) This low frequency is strongly correlated to an azimuthal mode (m=1) (POF Deck & Thorigny 2007, POF Weiss et al. (2009,2011), AIAA Pain et al. 2014) influence of the struts observed during the experiments (NLR DNW- HST ESA-TRP Ariane 5, Geurts, 2010) on St D =0.2 Well-documented database (Kulites, TR-PIV) (Schrijer et al. POF 2014 & EUCASS 2011) 8

9 Content Purpose What is the need in applied aerodynamics? What validation means for applied aerodynamics? Proposal: coupled numerical strategy ZIBC Ariane 5: A typical example of complexity Big data: the next step 9

10 What is the need in applied aerodynamics? Underlying issue: What are the acceptable assumptions that can be made fitting applied aerodynamics constraints? H1: Complex geometrical parts are often technological details leading to the occurrence of massively separated flows H2: The selected modeling must be robust and return the blockage effect (first expectation with massively separated flows) H3: Need for increased reactivity (e.g. design of future space launchers) 10

11 What is the need in applied aerodynamics? Physical understanding of the influence of technological details on the dynamics of unsteady flow fields 11

12 What is the need in applied aerodynamics? QUESTIONS Physical understanding of the influence of technological details on the dynamics of unsteady flow fields 12

13 What is the need in applied aerodynamics? QUESTIONS What can be done without throwing our favorite mature methodology?! Physical understanding of the influence of technological details on the dynamics of unsteady flow fields 13

14 What is the need in applied aerodynamics? QUESTIONS What can be done without throwing our favorite mature methodology?! 1. What do we mean by mature? Physical understanding of the influence of technological details on the dynamics of unsteady flow fields 14

15 What is the need in applied aerodynamics? QUESTIONS What can be done without throwing our favorite mature methodology?! 1. What do we mean by mature? 2. What is our favorite methodology? Physical understanding of the influence of technological details on the dynamics of unsteady flow fields 15

16 What is the need in applied aerodynamics? QUESTIONS What can be done without throwing our favorite mature methodology?! 1. What do we mean by mature? 2. What is our favorite methodology? 3. What is our proposal to go further? Physical understanding of the influence of technological details on the dynamics of unsteady flow fields 16

17 What is the need in applied aerodynamics? QUESTIONS What can be done without throwing our favorite mature methodology?! 1. What do we mean by mature? Physical understanding of the influence of technological details on the dynamics of unsteady flow fields 17

18 Content Purpose What is the need in applied aerodynamics? What validation means for applied aerodynamics? Proposal: coupled numerical strategy ZIBC Ariane 5: A typical example of complexity Big data: the next step 18

19 Levels of validation (Sagaut & Deck, PTRSA, 2009) 19

20 Levels of validation In this presentation : up to level 5 Level 6 : N/A (statistically steady flow) Prior to the validation : introduction of an additional level 0 Glimpse into the instantaneous flow 20 *Not applicable

21 From the BF approach to the BF / IB coupling Body-fitted (BF) S3Ch GC Very Low Geometrical Complexity (GC) Validation level (VL) Physical analysis level () VL 21

S3Ch test case with the BF approach Body-fitted (BF)

(VL) Physical analysis level () GC VL Very Low M 0.

22 S3Ch test case with the BF approach Body-fitted (BF) Up to Geometrical Complexity (GC) Validation level (VL) Physical analysis level () GC VL Very Low M 0.7 N xyz 12M Re D Unsteady I/O (T sim =0.2 s) (Tb) 0D D D 0.5 3D 2 Cp rms (x) m=1 Weiss P.-E., Deck S., Robinet, J.-C. and Sagaut P., On the dynamics of axisymmetric turbulent separating/reattaching flows, Physics of Fluids, Volume 21, ,

23 From the BF approach to the BF / IB coupling Body-fitted (BF) S3Ch GC VL Very Low When the geometry becomes more complex: Geometrical Complexity (GC) Validation level (VL) Physical analysis level () Time for setting up the simulation = α Time for running it with α 1 (growing with the complexity of the grid to build) Time for post-processing the simulation = Time for running it with 1 (growing with the amount of data generated) This permits to define what is the minimum amount of data to sample to claim to be a Big Data owner BUT people from the structured world have NOT given up! 23

24 From the BF approach to the BF / IB coupling Body-fitted (BF) S3Ch NLR GC Very Low GC Low Geometrical Complexity (GC) Validation level (VL) Physical analysis level () VL VL 24

001 1D 0.05 2D 0.7 3D 2.5 Weiss P.-E. and Deck S.

25 NLR test case with the BF approach Body-fitted (BF) Up to GC Low VL Geometrical Complexity (GC) Validation level (VL) Physical analysis level () M 0.8 N xyz 24M Re D Unsteady I/O (T sim =0.2 s) (Tb) 0D D D 0.7 3D 2.5 Weiss P.-E. and Deck S., Zonal Detached Eddy Simulation of the flow dynamics on an Ariane 5-type afterbody, 4th European Conference for Aerospace Sciences, Flight Physics, Launcher Aerodynamics,

26 From the BF approach to the BF / IB coupling Body-fitted (BF) S3Ch NLR 3-body GC Very Low GC Low GC Intermediate VL VL VL Geometrical Complexity (GC) Validation level (VL) Physical analysis level () 26

3-body test case with the BF approach Body-fitted (BF) Up to

level () GC VL Intermediate M 0.7 N xyz 75M Re D 1.

7 3D 3 Pain, R., Weiss P.-E. and Deck S.

27 3-body test case with the BF approach Body-fitted (BF) Up to Geometrical Complexity (GC) Validation level (VL) Physical analysis level () GC VL Intermediate M 0.7 N xyz 75M Re D Unsteady I/O (T sim =0.2 s) (To) 0D D D 0.7 3D 3 Pain, R., Weiss P.-E. and Deck S., Zonal Detached Eddy Simulation of the flow around a simplified launcher afterbody, AIAA Journal, Volume 52, Issue 9, , 2014

28 From the BF approach to the BF / IB coupling Body-fitted (BF) S3Ch NLR 3-body GC Very Low GC Low GC Intermerdiate VL VL VL Geometrical Complexity (GC) Validation level (VL) Physical analysis level () Struts GC Difficult VL 28

05 2D 0.9 3D 5 Fluctuating pressure coefficient on the nozzle Weiss P.-E. and Deck S.

29 Struts test case with the BF approach Body-fitted (BF) Up to Geometrical Complexity (GC) Validation level (VL) Physical analysis level () GC VL Difficult M N xyz 120M Re D Unsteady I/O (T sim =0.2 s) (Tb) 0D D D 0.9 3D 5 Fluctuating pressure coefficient on the nozzle Weiss P.-E. and Deck S., ZDES of the flow dynamics on an Ariane 5-type afterbody with and without struts, 6th European Conference for Aerospace Sciences, Flight Physics, Launcher Aerodynamics, 2015

30 From the BF approach to the BF / IB coupling Body-fitted (BF) S3Ch NLR 3-body GC Very Low GC Low GC Intermerdiate VL VL VL Geometrical Complexity (GC) Validation level (VL) Physical analysis level () Struts GC Difficult VL Full GC Insane! VL 30

From the BF approach to the BF / IB coupling Body-fitted (BF) S3Ch NLR 3-body GC Very Low GC Low GC Intermediate VL VL VL Geometrical Complexity (GC) Validation level (VL) Physical

31 From the BF approach to the BF / IB coupling Body-fitted (BF) S3Ch NLR 3-body GC Very Low GC Low GC Intermediate VL VL VL Geometrical Complexity (GC) Validation level (VL) Physical analysis level () Struts GC Difficult VL Full GC Insane! VL UNDONE WHY NOT? BECAUSE building a grid topology often means this Saint Girons' Church and its roof structure (Monein, France) 31

32 From the BF approach to the BF / IB coupling Body-fitted (BF) S3Ch NLR 3-body GC Very Low GC Low GC Intermediate VL VL VL Geometrical Complexity (GC) Validation level (VL) Physical analysis level () Struts GC Difficult VL Coupling: BF / IB Full GC Insane! VL UNDONE 32

33 What is the need in applied aerodynamics? QUESTIONS What can be done without throwing our favorite mature methodology?! 1. What do we mean by mature? 2. What is our favorite methodology? Physical understanding of the influence of technological details on the dynamics of unsteady flow fields 33

To model the flow: Zonal Detached Eddy Simulation (ZDES)

Gradient-induced TBL-dependent Multi-resolution approach, i.

aims at treating all classes of flow problems in a single

34 To model the flow: Zonal Detached Eddy Simulation (ZDES) developed by ONERA since 2002 Geometry-induced Gradient-induced TBL-dependent Multi-resolution approach, i.e. covers the full range of modelling from RANS to LES ZDES aims at treating all classes of flow problems in a single model Ref: Deck (AIAAJ. 43(11)), 2005 & Deck (Theo. & Comp. Fluid Dynamics, 2012) 34

35 Content Purpose What is the need in applied aerodynamics? What validation means for applied aerodynamics? Proposal: coupled numerical strategy ZIBC Ariane 5: A typical example of complexity Big data: the next step 35

36 Proposal: coupled numerical strategy ZIBC Goals : Preserve the level of validation of ZDES & increase level of representativeness of the configurations with a low intrusive additional numerical approach Definition of a global coupled framework ZIBC : (Zonal Immersed Boundary Conditions ) A numerical approach (RANS, URANS, ZDES, LES, DNS, ) + zonal IBC Use of ZDES: efficient on various unsteady flows in applied aerodynamics and in particular in the space launcher field (POF Deck & Thorigny, 2007, POF Weiss et al. 2009, POF Weiss & Deck 2011, JFM Deck et al. 2014, AIAA J Pain et al. 2014, etc ) 36

37 Overview of the zones defined for the coupling 37

structured mesh 2 nd order schemes (time

38 Description of the ZIBC strategy Source term target u 0 v 0 w 0 ~ 0 For each solid center of the cells Numerical set up Finite volume method Multi-block structured mesh 2 nd order schemes (time & space) ZDES mode II in IBC zones IB (Immersed Boundary) + AIAA Journal, Mochel, Weiss, Deck, Vol. 52, Issue 12, 2014 BF (Body-fitted) 38

39 From the BF approach to the BF / IB coupling Body-fitted (BF) S3Ch NLR 3-body GC Very Low GC Low GC Intermediate VL VL VL Geometrical Complexity (GC) Validation level (VL) Physical analysis level () Struts GC Difficult VL Coupling: BF / IB Full Skirt GC Insane! GC Low VL VL UNDONE 39

Skirt test case with the BF / IB coupling Coupling: BF / IB Up to GC Low

level () Mode I M 0.7 - N xyz 12M Re D 1.

5 3D 2 Mochel, L., Weiss P.-E. and Deck, S.

40 Skirt test case with the BF / IB coupling Coupling: BF / IB Up to GC Low VL Geometrical Complexity (GC) Validation level (VL) Physical analysis level () Mode I M N xyz 12M Re D Mode II Unsteady I/O (T sim =0.2 s) (Tb) 0D D D 0.5 3D 2 Mochel, L., Weiss P.-E. and Deck, S. Zonal Immersed Boundary Conditions: Application to a high Reynolds number afterbody flow, AIAA Journal, Volume 52, Issue 12, ,

41 From the BF approach to the BF / IB coupling Body-fitted (BF) S3Ch NLR 3-body GC Very Low GC Low GC Intermediate VL VL VL Geometrical Complexity (GC) Validation level (VL) Physical analysis level () Struts GC Difficult VL Coupling: BF / IB Full Skirt GC Insane! GC Low VL VL GC VL Struts Difficult UNDONE 41

Struts test case with the BF / IB coupling Coupling: BF / IB

Physical analysis level () GC VL Difficult M 0.

2 s) (Tb) 0D 0.001 1D 0.05 2D 0.7 3D 3 Weiss P.-E. and Deck S.

method with ZDES: application to the interactions in a full

42 Struts test case with the BF / IB coupling Coupling: BF / IB Up to Geometrical Complexity (GC) Validation level (VL) Physical analysis level () GC VL Difficult M N xyz 75M Re D Unsteady I/O (T sim =0.2 s) (Tb) 0D D D 0.7 3D 3 Weiss P.-E. and Deck S., On the coupling of a zonal body-fitted/immersed boundary method with ZDES: application to the interactions in a full space launcher afterbody flow, 4th International Conference on Turbulence and Interactions, 2015.

43 From the BF approach to the BF / IB coupling Body-fitted (BF) S3Ch NLR 3-body GC Very Low GC Low GC Intermerdiate VL VL VL Geometrical Complexity (GC) Validation level (VL) Physical analysis level () Struts GC Difficult VL Coupling: BF / IB Full Skirt GC Insane! GC Low GC Struts Difficult Full GC Insane! VL VL VL VL UNDONE 43

44 From the BF approach to the BF / IB coupling Body-fitted (BF) S3Ch NLR 3-body GC Very Low GC Low GC Intermerdiate VL VL VL Geometrical Complexity (GC) Validation level (VL) Physical analysis level () Struts GC Difficult VL Coupling: BF / IB Full Skirt GC Insane! GC Low GC Struts Difficult Full GC Insane! VL VL VL VL UNDONE 44

45 Content Purpose What is the need in applied aerodynamics? What validation means for applied aerodynamics? Proposal: coupled numerical strategy ZIBC Ariane 5: A typical example of complexity Big data: the next step 45

Full test case with the BF / IB coupling Geometrical Complexity (GC) Validation level (VL) Physical analysis level () Coupling: BF / IB GC Insane! VL M 0.8 - N xyz 75M Re D 1.

Validation Well-documented (steady and unsteady measurements) Permits to access different levels of validation 4. Physical analysis Unsteady I/O (T sim =0.2 s) (Tb) 0D 0.001 1D 0.05 2D 0.

46 Full test case with the BF / IB coupling Geometrical Complexity (GC) Validation level (VL) Physical analysis level () Coupling: BF / IB GC Insane! VL M N xyz 75M Re D Why is Ariane 5 a good test case in applied Aerodynamics? 1. Realistic and complex geometry 2. Advanced numerical simulation needed: Reynolds number flow Massively separated flows 3. Validation Well-documented (steady and unsteady measurements) Permits to access different levels of validation 4. Physical analysis Unsteady I/O (T sim =0.2 s) (Tb) 0D D D 0.7 3D 3 validation level allows a deeper insight into physics using the advanced numerical simulations (here ZDES + BF / IB) 5. Perspectives Complex configurations in aerodynamics (e.g. Ariane 5 and future launchers) Need for increased reactivity Decrease the time to assess the effect of a technological detail Weiss P.-E. and Deck S., On the coupling of a zonal body-fitted/immersed boundary method with ZDES: application to the interactions on a realistic space launcher afterbody flow, Computers & Fluids, revised,

47 Ariane 5: Description of the test case L D (on 480 procs) N xyz = 75 x Δϕ 1 (N ϕ = 356) M 0 = 0.8 Re D 1.2 x :60 sub-scale model & L/D =

48 Ariane 5: Description of the ZIBC approach CAD Mesh CAD (.stl) Tag d w Initial wall distance (d w ) fluid/solid tagging of the multi-block mesh Updated d w 48

49 First glimpse into the flow 49 (thick slices of iso-contours of the streamwise velocity)

50 First glimpse into the flow Y-Z plane Booster (B) plane Coherent structures colored by the sign of vorticity (Red for positive values and blue for negative values) Wide range of turbulent scales 50

Parallel to physical validation: numerical validation Mode 0

levels Existence of a dissipative area Correct integral

separation Mode II Low eddy viscosity levels Wide range of

51 Parallel to physical validation: numerical validation Mode 0 Mode II Upstream from the separation Mode 0 eddy viscosity levels Existence of a dissipative area Correct integral properties of the incoming boundary layer Downstream the separation Mode II Low eddy viscosity levels Wide range of turbulent scales resolved Rapid development of the shear layer pairing process 51

52 Levels of validation In this presentation : up to level 4/5 Level 6 : N/A (statistically steady flow) Prior to the validation : introduction of an additional level 0 Glimpse into the instantaneous flow 52 *Not applicable

53 First-order statistics (level 2) 53

54 Second-order statistics (level 3) 54

55 Levels of validation In this presentation : up to level 4/5 Level 6 : N/A (statistically steady flow) Prior to the validation : introduction of an additional level 0 Glimpse into the instantaneous flow 55 *Not applicable

56 Single-point spectra (level 4) : Exp. NLR : Sim. ZIBC 56

57 Further physical analysis : flow topology Once the validation has been performed: it permits to go deeper into physical interpretation (NB) plane similarity with axisymmetric flow topologies Flow seems to be symmetrical with respect to the booster and nobooster planes but it is NOT! 57 (B) plane quasi-zeromass-flow area strong sensitivity of the confined area near the struts

U/U =0 Planar symmetry (without technological details) breaks

58 Further physical analysis : symmetry breaking Instantaneous iso-surf. U/U =0 Mean iso-surf. U/U =0 Planar symmetry (without technological details) breaks into a central symmetry (with technological details) The flow preserves the symmetry of the geometry 58

59 Further physical analysis : symmetry breaking Solid rotation of the flow compared to launcher without technological details ( clean boosters and main stage) 59

60 From the BF approach to the BF / IB coupling Body-fitted (BF) S3Ch NLR 3-body GC Very Low GC Low GC Intermerdiate VL VL VL Geometrical Complexity (GC) Validation level (VL) Physical analysis level () Struts GC Difficult VL Coupling: BF / IB Full Skirt GC Insane! GC Low GC Struts Difficult Full GC Insane! VL VL VL VL UNDONE 60

61 From the BF approach to the BF / IB coupling Body-fitted (BF) S3Ch NLR 3-body GC Very Low GC Low GC Intermediate VL VL VL Geometrical Complexity (GC) Validation level (VL) Physical analysis level () Struts GC Difficult VL Coupling: BF / IB Full Skirt GC Insane! GC Low GC Struts Difficult Full GC Insane! VL VL VL VL UNDONE DONE! 61

62 Content Purpose What is the need in applied aerodynamics? What validation means for applied aerodynamics? Proposal: coupled numerical strategy ZIBC Ariane 5: A typical example of complexity Big data: the next step 62

Big data: the next step What we can do: Perform complex flow simulations on realistic configurations NB: The ZDES BF /

resolution requirements remains the same What we want to do: Extract more flow physics (e.g.

e. a human) Unsteady I/O (T sim =0.2 s) (Tb) (maxima for the presented configurations) 0D ~0.001 1D 0.

63 Big data: the next step What we can do: Perform complex flow simulations on realistic configurations NB: The ZDES BF / IB coupling allows rapid local geometrical changes preserving the same postprocessing chain given the mesh with high resolution requirements remains the same What we want to do: Extract more flow physics (e.g. dynamic features of the space-time flow field) Big data: DATA (see the data set sizes) BIG can stand for Big Brain i.e. a supercomputer to analyse (post-process, visualize) the simulations oriented by a less big brain (i.e. a human) Unsteady I/O (T sim =0.2 s) (Tb) (maxima for the presented configurations) 0D ~ D D 3D 1 5 ONERA s Stelvio (SGI ICE 8200 / ICE-X supercomputer) 63

64 Big data: the next step What are the bottlenecks of post-processing / visualization in Aerodynamics? (Painful or unfeasible tasks) Storage itself is not really the problem: You can collect several small black boxes of N Terabytes each Even on adapted hardware: - I/O remains a strong bottleneck - latency during manipulation constitutes a real limitation to explore the flow Read/Write time without any operations to alter and analyze the raw data remains already a bottleneck!!! 64

65 Big data: the next step Can constitute a painful task but almost always feasible Unfeasible task IF the post-processing has not been thought ahead 65

100 khz. 4.5 10 6 points (2 T-bytes 30% of the grid) 6.

66 Big data: the next step Acquisition of 3D instantaneous data fields over a total period T=200 ms and a sampling rate equal to 100 khz points (2 T-bytes 30% of the grid) points (3 T-bytes 20% of the grid) (Pain, Weiss, Deck, AIAA J. 2013) 66

67 Big data: the next step Spectral analysis of the fluctuating data field (3D Fourier analysis) Without booster (Pain, Weiss, Deck AIAA J. 2013) With boosters 67

68 Big data: the next step St D = 0.2 St D = 0.6 St D = D DMD modes (see JFM Rowley et al. (2009) and JFM Schmid (2010)) Pain R., Weiss P.-E. and Deck S., Three-dimensional spectral analysis of an axisymmetric separating/reattaching flow, TSFP 8, International Symposium On Turbulence and Shear Flow Phenomena, August

69 Conclusion and future work Conclusion 1 Reproduce the high Reynolds number turbulent flow of a full launcher type geometry (Ariane 5) quantitatively with ZDES + BF / IB The first and second order statistics are well-reproduced Same broad band spectrum of the side load as in the experiments 2 Improve the understanding of the influence of the struts Symmetry breaking with the technological details (not existing without) Strong signature of the protuberances in the flow field (influencing the side loads levels) Future work Deep analysis of the pressure field for evidencing Fourier modes (Big data: some terabytes can already be significant due to the post-processing) Different types of IBC (i.e. formulations) Fine reconstruction of wall quantities 69

70 Thanks for your attention 70

Second Symposium on Hybrid RANS-LES Methods, 17/18 June 2007

Second Symposium on Hybrid RANS-LES Methods, 17/18 June 2007 1 Zonal-Detached Eddy Simulation of Transonic Buffet on a Civil Aircraft Type Configuration V.BRUNET and S.DECK Applied Aerodynamics Department The Buffet Phenomenon Aircraft in transonic conditions Self-sustained