revolutionary computational aerosciences (rca)

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1 Transformational Tools and Technologies Project Revolutionary Computational Aerosciences (RCA) Research Portfolio and CFD 2030 Mujeeb R. Malik Technical Lead, RCA NASA Langley Research Center Cetin C. Kiris Head, Computational Aerosciences Branch NASA Ames Research Center HiFi-TURB Project Kick-Off Meeting Brussels, Belgium July 2 nd , 2019

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Page 1: Revolutionary Computational Aerosciences (RCA)

1

Transformational Tools and Technologies Project

Revolutionary Computational Aerosciences (RCA)Research Portfolio and CFD 2030

Mujeeb R. MalikTechnical Lead, RCA

NASA Langley Research Center

Cetin C. KirisHead, Computational Aerosciences Branch

NASA Ames Research Center

HiFi-TURB Project Kick-Off MeetingBrussels, Belgium

July 2nd, 2019

Page 2: Revolutionary Computational Aerosciences (RCA)

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Outline

• NASA Aeronautics Organization Structure

ARMD à TACP à TTT à RCA

• CFD Vision 2030

• Revolutionary Computational Aerosciences (RCA) Research Portfolio

• Example Highlights

• Foundational Research in RCA à ARMD and other Mission Directorates

• Summary

Page 3: Revolutionary Computational Aerosciences (RCA)

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NASA Aeronautics Programs and Projects

AdvancedAir Vehicles

Projects• Advanced Air Transport

Technology• Revolutionary Vertical Lift

Technology• Commercial Supersonic

Technology• Hypersonic Technology

Integrated Aviation Systems

Projects• Unmanned Aircraft

Systems Integration in the National Airspace System

• Flight Demonstrations and Capabilities

• Low Boom Flight Demonstrator

TransformativeAeronautics Concepts

Projects• Convergent Aeronautics

Solutions• Transformational Tools

and Technologies• University Innovation

AirspaceOperations and Safety

Projects• Airspace Technology

Demonstrations• UAS Traffic Management• System-Wide Safety• ATM-X

Akbar Sultan: DirectorDr. James Kenyon: Director Dr. Ed Waggoner: Director Dr. John Cavolowsky: Director

+

X-planes/test environment

+

Critical cross-cutting tool development

ARMD PROGRAMS

NASA Mission Directorates

Aeronautics Research (ARMD) Dr. Jaiwon Shinn, AA

Human Exploration and Operations(HEOMD)

Science(SMD)

Space Technology(STMD)

Aerosciences Evaluation & Test Capability Office

www.nasa.gov

Page 4: Revolutionary Computational Aerosciences (RCA)

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§ Revolutionary Computational Aerosciences (RCA)

§ Innovative measurements

§ Multi-disciplinary analysis and optimization (MDAO)

§ Combustion modeling and technologies

§ Propulsion and flight controls

§ Materials and structures for next generation aerospace systems

§ Autonomous systems

Transformational Tools and Technologies (T3) Project

RCA develops high-fidelity, physics-based computational analysis capability informed by CFD Vision 2030 study recommendations

T3 project performs deep-discipline research and engages in development of first-of-a-kind capabilities to analyze, understand,

predict, and measure performance of aviation systems; research and development of “tall-pole” technologies; all of which enable design of

advanced aeronautics systems.

Page 5: Revolutionary Computational Aerosciences (RCA)

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RCA Research Portfolio Guided by: CFD 2030 Technology Development Roadmap

Visualization

Unsteady, complex geometry, separated flow at flight Reynolds number (e.g., high lift)

2030202520202015

HPCCFD on Massively Parallel Systems

CFD on Revolutionary Systems(Quantum, Bio, etc.)

TRL LOWMEDIUMHIGH

PETASCALE

Demonstrate implementation of CFD algorithms for extreme parallelism in

NASA CFD codes (e.g., FUN3D)

EXASCALE

Technology Milestone

Demonstrate efficiently scaled CFD simulation capability on an exascale system

30 exaFLOPS, unsteady, maneuvering flight, full engine

simulation (with combustion)

Physical Modeling

RANS

Hybrid RANS/LES

LES

Improved RST models in CFD codes

Technology Demonstration

AlgorithmsConvergence/Robustness

Uncertainty Quantification (UQ)

Production scalable entropy-stable solvers

Characterization of UQ in aerospace

Highly accurate RST models for flow separation

Large scale stochastic capabilities in CFD

Knowledge ExtractionOn demand analysis/visualization of a 10B point unsteady CFD simulation

MDAO

Define standard for coupling to other disciplines

High fidelity coupling techniques/frameworks

Incorporation of UQ for MDAO

UQ-Enabled MDAO

Integrated transition prediction

Decision Gate

YES

NO

NO

Scalable optimal solvers

YES

NODemonstrate solution of a representative model problem

Robust CFD for complex MDAs

Automated robust solvers

Reliable error estimates in CFD codes

MDAO simulation of an entire aircraft (e.g., aero-acoustics)

On demand analysis/visualization of a 100B point unsteady CFD simulation

Creation of real-time multi-fidelity database: 1000 unsteady CFD simulations plus test data with complete UQ of all data sources

WMLES/WRLES for complex 3D flows at appropriate Re

Integrated DatabasesSimplified data representation

Geometry and Grid Generation

Fixed Grid

Adaptive Grid

Tighter CAD couplingLarge scale parallel mesh generation Automated in-situ mesh

with adaptive control

Production AMR in CFD codes

Uncertainty propagation capabilities in CFD

Grid convergence for a complete configuration

Multi-regime turbulence-chemistry interaction model

Chemical kinetics in LES

Chemical kinetics calculation speedupCombustion

Unsteady, 3D geometry, separated flow(e.g., rotating turbomachinery with reactions)

CFD Vision 2030 Study report published in 2014

Page 6: Revolutionary Computational Aerosciences (RCA)

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Special Session at AIAA Aviation 2019

§ John Cavolowsky (NASA): NASA Aeronautics and CFD 2030

§ Jeffrey Slotnick (Boeing): Progress Towards CFD Vision 2030 – An Industrial Perspective for Air and Space Vehicle Applications

§ Gorazd Medic (UTRC): Impact of Vison 2030 on CFD Practices in Propulsion Industry

§ Eric Nielsen (NASA): High Performance Computing Towards CFD Vision 2030

§ Dimitri Mavriplis (U. Wyoming): Progress in CFD Discretizations, Algorithms and Solvers for Aerodynamic Flows

§ John Chawner (Pointwise): Progress in Geometry Modeling and Mesh Generation Toward the CFD Vision 2030

§ Philippe Spalart (Boeing): Turbulence Prediction in Aerospace CFD: Reality and the Vision 2030 Roadmap

Progress Towards CFD 2030 Vision

Session Sponsored by AIAA CFD Vision 2030 Integration Committee (IC)The newly formed IC was approved by AIAA in 2018

Page 7: Revolutionary Computational Aerosciences (RCA)

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“Three Pillars” of RCA ResearchRevolutionary Computational Aerosciences (RCA)

� Robustness/Reliability Ability to generate results with error bounds on every try, by a nonexpert user

Ø Robust solver technology/nonlinear stability

Ø Uncertainty quantification

� Cost/Efficiency Ability to compute faster by orders of magnitude compared to the current

practiceØ Exploit emerging HPC hardware capability

Ø Numerical algorithms (e.g., solvers, adaptive grids)

� ACCURACY Ability to accurately compute complex turbulent flows (e.g., transition, flow

separation, free shear flows, shock/boundary-layer interaction)Ø Numerical methods (e.g., HOMs), grids, boundary/initial conditions, etc.

Ø Improved physical modeling and simulations

§ CFD validation experiments (including physics experiment for model development) a critical need

CFD technology with above attributes will enable “Simulation-Based Engineering”:Ø Application to novel configurations, with confidence, for all NASA missions

– Airplanes (fixed-wing , vertical lift, manned/unmanned)

– Launch vehicles, airbreathing propulsion

– Entry, Descent, Landing

Ø Aircraft certification by analysis

Page 8: Revolutionary Computational Aerosciences (RCA)

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Technical Areas and Approaches• Physical Modeling and Simulations

§ LES/WMLES, hybrid RANS/LES and Lattice-Boltzmann Method

§ Laminar-turbulent transition modeling

§ Data driven modeling

• HPC Tools and Methods

§ Effective utilization of emerging HPC hardware

§ Accurate, efficient, and robust computational methods

§ Grid adaptation

§ Uncertainty quantification

• CFD Validation Experiments

§ Juncture flow

§ Flow separation (wall bump)

§ Turbulent heat flux

§ Shock/boundary-layer interaction

§ Supersonic jet flow

§ High-speed mixing layer

§ TDT aeroelastic experiment

RCA Research Portfolio

CFD

EXP

Outcome: Accurate, fully validated CFD capability

Foundational research aimed at solving technical challenges

Page 9: Revolutionary Computational Aerosciences (RCA)

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RCA’s Completed Technical Challenge

Identify and downselect critical turbulence, transition, and

numerical method technologies for 40% reduction in

predictive error against standard test cases for turbulent

separated flows, evolution of free shear flows and shock-

boundary layer interactions on state-of-the-art high

performance computing hardware.

Technical Challenge (TC) completed in 2018

Page 10: Revolutionary Computational Aerosciences (RCA)

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Efficient High-Fidelity Computational Tools for Predicting Maximum Lift on Transport Aircraft

RCA’s New Technical Challenge (TC) - 1

Develop and demonstrate computationally-efficient, eddy-resolving modeling tools that predict maximum lift coefficient (CLmax) for transport aircraft with equal or better accuracy than certification flight tests.

Eddy-resolving methods could enable reliable prediction throughout the flight envelope, but will be validated

specifically for CLmax prediction

Page 11: Revolutionary Computational Aerosciences (RCA)

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RCA’s New Technical Challenge (TC) - 2

Propulsion-related challenges

include inlet/distortion-tolerant fan

aerodynamics and aeromechanics

• Scale resolving simulations of inlet-fan interaction

• Enhanced CFD fan aeromechanics

Page 12: Revolutionary Computational Aerosciences (RCA)

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• Advancements in numerical methods and modeling implemented in NASA CFD codes

§ FUN3D

§ OVERFLOW

§ LAVA (NS + LBM)

§ EDDY (high-order spectral element)

§ GFR (flux reconstruction scheme)

Research Products

Multiple NASA projects fund capability developments in CFD codes

Page 13: Revolutionary Computational Aerosciences (RCA)

13

RCA Research Execution Strategy

• Foundational Research in Computational Fluid Dynamics (CFD) Breakthroughs cannot be predicted

§ Requires innovative thinking and a lot of trial and error

§ Find and challenge the best people available, let them learn from

failures/false starts

Ø Success will follow, but it cannot be scheduled

• Cross Centers Research Effort NASA Ames Research Center (ARC)

NASA Glenn Research Center (GRC)

NASA Langley Research Center (LaRC)

§ Additional Postdoctoral Fellows/Research Associates, where

needed

• Leverage Expertise Available at Universities and Industry through NASA Research Announcements (NRAs)

Critical for training future workforce

Page 14: Revolutionary Computational Aerosciences (RCA)

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Currently Funded RCA NRAs

Physical Modeling & Simulations:• Improving the accuracy and efficiency of scale resolving simulations for favorable and adverse

pressure gradient flows; U Colorado (Kenneth Jansen)

• Adaptivity in wall-modeled large eddy simulations of complex three-dimensional flows; U Maryland

(Johan Larsson).

• Assessment of wall-modeled LES in nonequilibrium flows with emphasis on grid independency; U

Pennsylvania (George Park)

• Scale-resolving turbulent simulations through adaptive high-order discretizations and data-enabled

model refinements; U Michigan (Krzysztof Fidkowski)

• Validation of wall models for LES with application to the NASA Common Research Model; Stanford

(Parviz Moin)

HPC Tools & Methods:• Scalable hierarchical CFD solvers for future exascale architectures; Stanford (Juan Alonso)

• Efficient and robust CFD solvers for exascale architectures; U Wyoming (Dimitri Mavriplis)

• A stochastic framework for computation of sensitivities in chaotic flows; U Pittsburg (Hessam Babaee)

• Parallel geometry for design and analysis; Syracuse U (John Dannehoffer)

CFD Validation Experiments:• Smooth wall separation over bumps: Benchmark experiments for CFD validation; VA Tech (Kevin

Lowe).

• Benchmark experimental measurements of turbulent, compressible mixing layers for CFD validation;

U-Illinois (Craig Dutton)

Certification by Analysis:• Requirements for aircraft certification by analysis; Boeing (Dinesh Naik)

NASA Research Announcements (NRAs) provide a mechanism to collaborate

with academia and industry, a recommendation of the CFD Vision 2030 Study

Page 15: Revolutionary Computational Aerosciences (RCA)

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Some Technical Highlights

Page 16: Revolutionary Computational Aerosciences (RCA)

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CFD Validation ExperimentsA critical element of the RCA research portfolio

• Recommendation of CFD Vision 2030 Study: NASA should lead efforts to develop and execute integrated experimental testing and computational validation campaigns− Experiments to provide data for development of advanced turbulence

models/prediction capability is a critical need

• A CFD validation experiment should include the measurement of all information, including boundary conditions, geometry information, and quantification of experimental uncertainties, necessary for a thorough and unambiguous comparison to CFD predictions

• All data sets made available to interested parties for analysis

Page 17: Revolutionary Computational Aerosciences (RCA)

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Juncture Flow Experiment

• Unique on-board Laser-Doppler Velocimetry (LDV)

system specifically designed for measuring the

near-wall juncture region flow field through windows

Off-body velocities and moments (LDV and some

PIV)

Model surface pressures (steady/unsteady)

• Experiment performed in NASA 14x22 ft wind tunnel

With careful attention to measuring flow-field BC

• Comparisons made using OVERFLOW and FUN3D

Nonlinear turbulence modeling (e.g., quadratic

constitutive relations or a full Reynolds stress model)

necessary to predict size of corner separation

Some disagreement between the RANS models and

the measured Reynolds stresses in the corner region

CFD EXP

POC: Chris Rumsey (LaRC), Mike Kegerise (LaRC), and Dan Neuhart (LaRC).

LDV system in use: (Right) near wing LE;

(Left) near TE

Page 18: Revolutionary Computational Aerosciences (RCA)

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LDV Profiles at 1168.4 mm from nose, a=5�LDV measurement locationMean velocities Reynolds normal stresses

Reynolds shear stresses Turbulent kinetic energy

u’u’u’ triple products

Juncture Flow Experiment

Wealth of detailed flow physics data acquired in the juncture flow experiment at multiple locations

POC: Chris Rumsey (LaRC), Mike Kegerise (LaRC), and Dan Neuhart (LaRC).

Mean flow Normal stresses

Shear stresses Kinetic energy Triple products

Page 19: Revolutionary Computational Aerosciences (RCA)

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Turbulent Heat Flux (THX) Experiments

THX Phase 3 nozzle and plate (single injector hole) installed in NASA GRC AAPL facility.

Raman measurements of mean temperature.

POC: Nick Georgiadis (GRC), Mark Wernet (GRC), and Randy Locke (GRC/VPL).

THX Phase 4 plate concept (3 arrays of cooling holes).

PIV measurements of mean velocity.

TESTING• Phase 1 experiments: low speed/temperature cooling flow

• Phase 2 round jet experiments: Maximum Tt=1000 K and jet Mach

= 0.9 - NASA GRC Acoustic reference nozzle (ARN)

• Phase 3 square nozzle with plate having single cooling injector

(similar flow conditions as step 2, multiple blowing ratios)

• Phase 4 same nozzle as Phase 3, 3 arrays of 45 cooling holes

Data for improving models for turbulent heat flux and cooling hole boundary conditions. High-quality flow field data includes:

Mean velocities and temperatures, turbulence/thermal statistics –

using PIV and Raman; surface temperatures using TCs and IR

imagery. Well documented inflow conditions for CFD modeling.

Experimentalists and CFD modelers involved in all aspects of

experiments from test planning through experimentation.

• Heated film injection• Thru single hole and three holes • (DT=75 deg F)

Mainstream flow (30 ft/sec, room temp)

Flat plate

• Hot-wire (T’)• PIV (u’, v’, w’)• Thermocouples• Pitot probes• Raman spectroscopy

Computational analysis is underway

Page 20: Revolutionary Computational Aerosciences (RCA)

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• Pressure gradients imposed with wall-mounted hump

Attached flow, incipient separation and massive separation Rotation provides parameters for data-driven modeling Geometric symmetries provide key UQ information about

geometry uncertainties and flow non-uniformities Instrumentation: Optical (LDV, PIV), pressure rake, hot-

wire, temperature, skin-friction (indirect)

!"#$$%& =1.83 m

! "#$

$%&=

1.83

m

()

*+!,#-.

Smooth Wall Separation Experiments over Bumps(NRA to Virginia Tech)

Wall-mounted hump in VA

Tech Stability Tunnel

POC: Todd Lowe et al. (Virginia Tech)

• Document uncertainties Rotated bump, same location in the tunnel (quantifies geometric nonuniformity)

Rotated bump mounted on other side of the tunnel (quantifies flowfield

nonuniformity)

-30 -20 -10 0 10 20 30-30

-20

-10

0

10

20

30

1

2

3

4

5

6

7

8

Z, [

in]

Bump planform

Page 21: Revolutionary Computational Aerosciences (RCA)

21

Compressible Mixing Layer Experiments (NRA to U-Illinois)

• CFD validation-quality measurements of compressible

mixing layer to document effects on growth rate,

Reynolds stress field, turbulent large-scale structure,

mixing (including thermal mixing)

Convective Mach numbers, Mc = 0.19, 0.37, 0.54, 0.74,

0.86 and 1.0

Schlieren and planar laser-sheet visualizations, static and

pitot pressure measurements, with emphasis on stereo PIV

measurements of mean and turbulent velocity fields

Complete documentation of the inflow conditions/boundary

conditions for each case, especially the boundary layers on

all incoming walls to the mixing layer

Complete uncertainty analysis of entire spatial fields of

pressure and SPIV mean and turbulence velocity

measurements

POCs: Craig Dutton, Greg Elliott (UIUC)

Self-similarity of mean

velocity profiles

Mc = 0.19 mixing layer recorded

at 60,000 FPS

Page 22: Revolutionary Computational Aerosciences (RCA)

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Wall-resolved LES for Axisymmetric Transonic Bump

)ORZ

VHSDUDWLRQ�OLQH

UHDWWDFKPHQW�������UHJLRQ

Mach number = 0.875

• Experimental set up

Bachalo and Johnson, AIAA J. 24(3), 1986.

M = 0.875

Rec = 2.763 x 106

Reθ = 6600

• Flow simulation

4th-order compact scheme, with 10th-order filter

24 billion grid points to cover 120 degree azimuth

Free air assumption (tunnel wall effect ignored)

Reasonable agreement with measured wall

pressure and separation length

POCs: Ali Uzun (NIA), Mujeeb Malik(LaRC)

x/c

Cp

0.4 0.6 0.8 1 1.2 1.4 1.6

-1

-0.75

-0.5

-0.25

0

0.25

2 2 ft tunnel experiment1

6 6 ft tunnel data from Horstman and Johnson2

6 6 ft tunnel data from Johnson3

Spalart et al. hybrid DNS-IDDES on 15-deg slice (8.5B points)baseline grid 30-deg slice (3B points)refined grid 120-deg slice (24B points)

Page 23: Revolutionary Computational Aerosciences (RCA)

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LAVA: NASA Wall-Mounted Hump

• LAVA curvilinear Navier-Stokes as well as Lattice-Boltzmann Method has been successfully

applied to NASA’s wall-mounted hump. Improvement of 96% in reattachment location.

Reattachment Location x/c [-] Error [%]

Greenblatt 1.105 -

RANS from TMR 1.26 14.02

DDES 1.34 21.26

ZDES + SEM 1.11 0.45

LBM + SEM 1.12 0.54

96 % improvementcompared to RANS

POC: Cetin Kiris et al. (ARC)

Page 24: Revolutionary Computational Aerosciences (RCA)

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Lesson Learned from RCA’s Completed TC

§ Reynolds-Averaged Navier-Stokes (RANS) failed to

accurately predict complex flow physics (e.g., RCA

standard test cases; CLmax)

§ Wall-modeled large eddy simulation (WMLES),

emerged as a promising approach for prediction of

CLmax, which is critical for aircraft certification by

analysis.

RANS

Mc = 0.38 mixing layer

HighliftJSMgeometrysuctionsideview

fuselage

flap

mainslat

flapsupport/trackfairings

Slatsupport

Slatsupportsresponsibleforvisiblewakesonsuctionside

Geometryhousesfuselage,slat,wing,flapandrelevantsupportstructures(nonacelleconsidered)Wingaspectratioof9.4;≈85%slatspan,≈75%flapspan(Yokokawaetal.2008)

WMLES

Eddy resolving methods development and validation will be the main thrust of the RCA’s new TC

WMLES w/ CharLES : surface flow velocityOutboard separation

Slat support wakes

Stanford NRA

JAXA Standard Model

Page 25: Revolutionary Computational Aerosciences (RCA)

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FUN3D Node-Level Performance Relative to Broadwell (BWL)

1.40.7

2.3

6.8

0.8 1.21.5

3.0

1.1 0.7

2.2

5.4

0.0

2.0

4.0

6.0

SKY KNL P100 V100

Meanflow Relative Performance

Meanflow Relative Performance/$

Meanflow Relative Performance/Watt

BWL BWL

Hardware Cores Baseline Code

BWL: 2× Xeon E5-2680v4 28 MPI Fortran

SKY: 2× Xeon Gold 6148 40 MPI Fortran

KNL: Intel Xeon Phi 7230 64 OpenMP Fortran (coloring)

P100: NVIDIA Pascal -- CUDA C++ (atomics)

V100: NVIDIA Volta -- CUDA C++ (atomics)

POC: Eric Nielsen (LaRC)

Page 26: Revolutionary Computational Aerosciences (RCA)

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FUN3D Performance on Summit

• Plot captures weak scaling on new

ORNL Summit system

(IBM Power9 + V100)

• Each node solves ~12.8M grid

points

5 nodes: 60M pts/267M elms

1,024 nodes: 13.2B pts/58B elms

• CPU curve is MPI+OpenMP with

3 ranks/socket (total of 6 per node)

with 168 total OpenMP threads per

node (smt4)

• GPU curve is MPI+CUDA:

3 ranks/socket shepherding 1 GPU each (total of 6 per node); all MPI via GPU Direct

• Nearly linear performance for both

• GPU performance is 23x-37x faster, depending on data point (generally around 25x)

~Ple

iade

s

~25%

of

Sum

mit

13.2B Points58B Elems

60M Points267M Elems

POC: Eric Nielsen (LaRC)

A potential 25-100x speedup in sight for CFD codes, from both hardware and algorithms

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Foundational research in RCA impacts focused applications

in ARMD and other mission directorates

Page 28: Revolutionary Computational Aerosciences (RCA)

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LAVA Hybrid RANS/LES : Jet-Noise Predictions

• Demonstrated jet noise prediction capabilities within LAVA curvilinear solver utilizing ZDES on

unheated axisymmetric round jet.

• Excellent Comparison between near-field CFD and experiments achieved

• Far-field predictions utilizing the permeable Ffowcs-Williams Hawkins (FWH) agree very

well with experiments. Improvements to previous simulations demonstrated.

(a) TKE centerline (a) PSD at 100D from nozzle exit

• Demonstrated improvement in prediction of length of potential core by 90% (RCA requirement 40%)

• Results published in AIAA/CEAS

Aeroacoustics Conference [AIAA 2019-2475]

POC: Cetin Kiris et al. (ARC)

Page 29: Revolutionary Computational Aerosciences (RCA)

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LAVA Hybrid RANS/LES : Jet-Surface Interaction Noise

• LAVA has demonstrated capabilities to capture noise shielding effects of an inserted plate in

close proximity to a jet. This is an important step towards predicting full airframe jet noise.

(a) Lipline velocity

(b) PSD at 100D from nozzle exit

trailing edge noise

POC: Cetin Kiris et al. (ARC)

Page 30: Revolutionary Computational Aerosciences (RCA)

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LAVA Lattice Boltzmann Simulations of Propeller Noise

Isocontours of Q-criterion colored by streamwise momentum from the simulated flow around the

propeller blade in hover

APPROACH: • The Lattice Boltzmann Method

• Solver extended with robust in-house boundary treatment

for moving blades which do not violate strict realizability of

the density distribution functions (The algorithm

development was supported by the TTT project and the

systematic validation using far-field noise measurements

from NASA Langley Research Center was supported by the

RVLT project.)

RESULTS: • Predicted both the performance and the aerodynamic noise

generated by the propeller with unprecedented accuracy

and turnaround times

SIGNIFICANCE:• First step towards predicting Urban Air Mobility Noise from

first principles using the Lattice Boltzmann solver

• Completely automated workflow without labor intensive

mesh generation

• Quick turnaround time - approximately 4000 core hours for

25 revolutions of isolated propeller (10% chord resolution)

• General formulation – Valid for arbitrarily moving (and

deforming) geometry

Far-field noise prediction compared to measurements conducted at LSAWT and SALT

facilities in NASA Langley

POC: Cetin Kiris et al. (ARC)

Page 31: Revolutionary Computational Aerosciences (RCA)

31

• Demonstrated the LBM

approach on the AIAA BANC III

Workshop Landing Gear

problem IV.

• Computed results compare

well with the experimental

data

• 12-15 times speed-up was

observed between LBM

and NS calculations.

• LBM has better memory access

and significantly lower floating

point operations relative to

WENO+RK4

• LBM has minimal numerical

dissipation

• Cartesian methods are very

successful for the right problems

LAVA Lattice-Boltzmann: Landing Gear

POC: Cetin Kiris et al. (ARC)

Page 32: Revolutionary Computational Aerosciences (RCA)

3232

Grid Sensitivity for PSD:Channel 5: Upper Drag Link

102 103 104

Frequency (Hz)

10�14

10�13

10�12

10�11

10�10

10�9

10�8

10�7

10�6

10�5

10�4

PSD

(psi

2 /H

z)

Channel 5

LB: 90 MillionLB: 260 MillionLB: 1.6 BillionEXP-UFAFF

Near Field PSD

Frequency (Hz)

102 103 104

10-4

10-7

10-10

10-13

3

4

85

7

13

15

1012

PS

D

(psi2

/Hz)

Surface Pressure Spectra at Sensor Locations

9

BANCIIISubmissions

LAVA Lattice-Boltzmann: Landing Gear Accuracy

POC: Cetin Kiris et al. (ARC)

Page 33: Revolutionary Computational Aerosciences (RCA)

34

Orion Launch Abort Acoustics Simulations

• CFD Vision 2030 Study recommends development

of “capability” computing and necessary algorithm

improvements to reach exa-scale

• Added a layer of fine-grain parallelism to the

Launch, Ascent, and Vehicle Aerodynamics

Cartesian solver to scale to 16,000+ cores

• Ongoing efforts target many-core machines with

an eye towards GPUs

• New capability used successfully for space

vehicles (HEOMD) to predict surface fluctuating

pressures over Orion launch abort vehicle (LAV)

for a range of abort scenarios

• Demonstrated excellent agreement with

experimental validation data from wind tunnel,

ground and flight tests

• Short enough turnaround time to affect design of

Orion Launch Abort System: completed 400,000

time steps on 630 million cell AMR mesh with

accelerating LAV in 30 days on 16,000 cores

Frequency (Hz)

Sound P

ressure

Level (d

B)

Shaded gray area

indicates +/- 1 dB

QM-1 EXP

Ignitio

n o

verp

ressure

Time (s)

Heat Shield Acoustics

- QM1 Measurements

- LAVA QM1v1 Simulation

QM-1 CFD

POC: Cetin Kiris et al. (ARC)

Page 34: Revolutionary Computational Aerosciences (RCA)

35

Orion Launch Abort Acoustics Simulations

-- Wind Tunnel Measurements

- LAVA Predictions

Frequency (Hz)

Frequency (Hz)

Frequency (Hz)

Sound P

ressure

Level (d

B)

Sound P

ressure

Level (d

B)

Shaded gray area is +/- 2

dB because of uncertainty

in simulation results due to

short integration time (0.02

s) vs experiment (5.00 s)

Transonic ascent abort at moderate angle of attack and side slip

Sound P

ressure

Level (d

B)

LAVA CFD

Volume rendering of pressure

fluctuations

POC: Cetin Kiris et al. (ARC)

Page 35: Revolutionary Computational Aerosciences (RCA)

36

Questions?36

Pressure on the vertical plane (white is high, black is low) for LAV transonic ascent abort at high angle of attack

Orion Launch Abort Acoustics Simulations

POC: Cetin Kiris et al. (ARC)

Page 36: Revolutionary Computational Aerosciences (RCA)

37

Summary

• RCA research portfolio is aimed at making progress towards CFD Vison 2030 and meeting the challenge of predicting aircraft CLmax Physical modeling

HPC

Numerical algorithms

Grid adaptation

CFD validation experiments

• Explore potential collaborations with HiFi-TURB project Leverage available expertise and data, for accelerated

progress toward CFD 2030 goals

Development of Accurate and Efficient Computational Tools will Enable Aircraft Certification by Analysis and Design of New Aerospace Configurations

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