1 Overview of NASA GRC’s Efforts In SWBLI 8 th Annual SWBLI Technical Interchange Meeting Mary Jo Long-Davis NASA Glenn Research Center Chief, Inlets and

1

Overview of NASA GRC’s Efforts In SWBLI

8th Annual SWBLI Technical Interchange Meeting Mary Jo Long-DavisNASA Glenn Research CenterChief, Inlets and Nozzles BranchApril 14, 2015

2NASAAeronautics Research

• NASA Aeronautics Reorganization

• NASA Glenn High Speed Inlet Technology

• NASA Glenn CFD Activities

• NASA Glenn Validation Experiments

Outline


NASA Aeronautics Research Six Strategic Thrusts

Safe, Efficient Growth in Global Operations• Enable full NextGen and develop technologies to substantially

reduce aircraft safety risks

Innovation in Commercial Supersonic Aircraft• Achieve a low-boom standard

Ultra-Efficient Commercial Vehicles• Pioneer technologies for big leaps in efficiency and

environmental performance

Transition to Low-Carbon Propulsion• Characterize drop-in alternative fuels and pioneer

low-carbon propulsion technology

Real-Time System-Wide Safety Assurance• Develop an integrated prototype of a real-time safety

monitoring and assurance system

Assured Autonomy for Aviation Transformation• Develop high impact aviation autonomy applications


Aeronautics Research Mission Directorate

Advanced Air Transport Technology

Project (AATT)

Advanced Air Vehicles (AAVP)

Airspace OperationsAnd Safety (AOSP)

Integrated Aviation Systems (IASP)

NASA Aeronautics Program Structure

Transformative AeronauticsConcepts (TACP)

Revolutionary VerticalLift Technology Project

(RVLT)

Commercial SupersonicTechnology Project

(CST)

Advanced CompositesProject (AC)

Aeronautics Evaluationand Test Capabilities

Project (AETC)

Airspace TechnologyDemonstrations Project

(ATD)

SMART NAS – Testbedfor Safe TrajectoryOperations Project

Safe AutonomousSystem Operations Project

(SASO)

EnvironmentallyResponsible

Aviation Project(ERA)

UAS Integration in the NAS Project

Flight Demonstrationand Capabilities Project

(FDC)

Leading EdgeAeronautics Research

for NASA Project(LEARN)

Transformative Toolsand Technologies Project

(T3)

Convergent AeronauticsSolutions Project

(CAS)

--------------------------- Mission Programs -------------------------------------- Seedling Program

Effective FY15


NASA Aeronautics FY 2016 Budget

Actual Enacted Request Outyears are NotionalBudget Authority ($M) FY 2014 FY 2015 FY 2016 FY 2017 FY 2018 FY 2019 FY 2020

Aeronautics $566.0 $651.0 $571.4 $580.0 $588.7 $597.5 $606.4

Airspace Operations and Safety

142.4 153.2 159.6 160.0 163.0

Advanced Air Vehicles 240.9 243.2 241.2 231.0 232.8

Integrated Aviation Systems 96.0 85.6 89.0 101.6 104.8

Transformative Aeronautics Concepts

92.1 98.0 98.9 104.9 105.8

Aviation Safety 80.0

Airspace Systems 91.8

Fundamental Aeronautics 168.0

Aeronautics Test 77.0

Integrated Systems Research 126.5

Aeronautics Strategy and Management

22.7

Programs & Projects guided by 6 Strategic Thrusts


What is the Advanced Air Vehicles Program (AAVP)?

Continues much of the research that was in the

Fundamental Aeronautics Program, with a new focus on research that is directly related to the newly defined strategic thrusts. It now houses the Advanced Composites Project that

was previously in the Integrated Systems Research Program. It also

includes the ground test portion of the former Aeronautics

Test Program.

Conducts fundamental research to improve aircraft performance and

minimize environmental impacts from subsonic air vehicles

Develops and validates tools, technologies and concepts to overcome key barriers, including noise, efficiency, and safety for vertical lift vehicles

Explores theoretical research for potential advanced capabilities and configurations for low boom

supersonic aircraft.

Conducts research to reduce the timeline for certification of composite structures for aviation

Ensures the strategic availability, accessibility, and capability of a critical suite of aeronautics

ground test facilities to meet Agency and national aeronautics testing needs.

Advanced Air Vehicles

Program

The Fundamental Aeronautics Program, ground test capabilities, atmospheric environments related safety.

ProjectsAdvanced Air Transport Technology

Revolutionary Vertical Lift Technology

Commercial Supersonics Technology

Advanced Composites

Aeronautics Evaluation and Test Capabilities

Mis

sion P

rogra

m


What is the Transformative Aeronautics Concepts (TAC) Program?

Solicits and encourages revolutionary concepts

Creates the environment for researchers to become immersed in trying out

new ideas

Performs ground and small-scale flight tests

Drives rapid turnover into new concepts

Cultivates multi-disciplinary, revolutionary concepts to

enable aviation transformation and harnesses convergence in

aeronautics and non-aeronautics technologies to create new opportunities in aviation

Knocks down technical barriers and infuses internally and

externally originated concepts into all six strategic thrusts identified by ARMD, creating

innovation for tomorrow in the aviation

system.

Provides flexibility for innovators to

explore technology feasibility and

provide the knowledge base for radical transformation.

Seedlin

g Pro

gram

Transformative Aeronautics

Concept Program

While mission programs focus on solving challenges, this program focuses on cultivating opportunities.

ProjectsCross Program Operations

Leading Edge Aeronautics Research for NASA

Transformative Tools & Technologies

Convergent Aeronautics Solutions






Outline


Design Study of LMCO N+2 Low Boom Supersonic Inlet

PROBLEMTask 1: Screening study to establish cane curve characteristic of the LMCO N+2 Low Boom Supersonic Inlet at cruise Mach 1.7Task 2: DOE study to establish the compatibility characteristics of the LMCO N+2 Low Boom Supersonic inlet and compare with the nominal requirementsTask 3: Analysis of the design implications of the unsteady interactions in the LMCO N+2 Low Boom Supersonic inlet by focusing on inlet buzz

OBJECTIVESFor Task 3, explore the following two questions:1. What is the triggering instability that initiates the inlet buzz cycle?2. What is the aerodynamic mechanism that sustains inlet buzz?

APPROACHComparisons were made between the detached eddy simulations (DES) of the Lockheed Martin Corporation (LMCO) N+2 inlet and schlieren photographs taken during the test of the Gulfstream Large Scale Low Boom (LSLB) inlet in the NASA 8x6 ft. Supersonic Wind TunnelRESULTS (Reference Anderson papers AIAA 2014-3799 and AIAA 2014-3801)• Extensive normal shock wave boundary layer separation along the spike

surface is the controlling mechanism which determines the onset of inlet buzz.

• The aerodynamic characteristics of a choked nozzle provide the feedback mechanism that sustains the buzz cycle by imposing a fixed mean corrected inlet weight flow during the buzz cycle.

• Comparisons between the DES analysis of the LMCO N+2 inlet and schlieren photographs taken in test of the Gulfstream (LSLB) inlet in the NASA 8x6 ft. SWT show a strong similarity both in flow field and shock wave structure during the buzz cycle.

SIGNIFICANCEResults demonstrate the value of detached eddy simulation for the design and understanding of supersonic inlet performance and operation.

-Commercial Supersonic Technologies (CST) Project

POC: Bernie Anderson (GRC)


Inward-Turning Low-Boom Inlet Designed

• A new parent flowfield for streamline-tracing was established based on the merging of an internal conical flowfield containing a leading-edge oblique shock with a Busemann flowfield containing a strong outflow oblique shock. [Summer Intern Sam Otto and Chuck Trefny (GRC)].

• A 3D inlet design was generated for Mach 1.7 and F404 conditions. A “cut-out” at the bottom allowed spillage of subsonic flow. [Otto and Trefny]

• CFD analysis with porous bleed predicts stable and acceptable performance. [Slater]


POC: Chuck Trefny and John Slater (GRC)


Proposed 8x6 SWT Test of Inward-Turning Low-Boom Inlet

NASA Inlet Adapter Cold-Pipe Mass Flow Plug

PROBLEMDemonstrate the performance of an inward-turning, high-performance, low-boom inlet with acceptable distortion levels to enable integration with a turbine engine.

OBJECTIVES OF PROPOSED 8x6 SWT TEST (1) Validate the effects of bleed and other boundary layer control schemes (e.g., vortex generators) on overall inlet

performance, (2) Provide better understanding of non-linear sub-critical phenomena, (3) Determine tolerance to angles of attack and yaw (4) Determine off-design Mach number performance

APPROACHPerform mechanical design, fabrication and GRC 8x6 Supersonic Wind Tunnel test of an inlet model. The model hardware will include using existing inlet adapter, cold-pipe, and mass flow plug. Existing adapter requires addition of rakes and hub to serve as Aerodynamic Interface Plane (AIP).

STATUS• NASA is currently modifying existing adapter

to include AIP 40-probe instrumentation• Advocating to include this test in FY16+ plans

for CST Project

SIGNIFICANCE of PROPOSED TESTTest data will validate performance and operability of an inward-turning low-boom inlet designed using a new method of merging Internal Conical Flow A (ICFA) and Busemann flowfields.

Sketch of proposed 8x6 Inlet Test Rig


POC: Chuck Trefny and John Slater (GRC)


Reference Mass Flow Plug Calibration Experiments (RMFPCE)PROBLEMWind tunnel performance testing of high-speed inlets is typically performed with a Mass-Flow Plug (MFP) in place of an engine. The MFP serves to control and measure the air flow through the inlet. Accurate measurement of the flow through the inlet is critical for engine flow matching and estimating inlet spillage which contributes to aircraft drag. The accuracy of mass-flow measurement with MFPs recently became a topic of interest when discrepancies were noted between the calibrations of two geometrically similar MFPs of approximately the same scale. Although deviation from ideal geometry was suspected as the cause, the study was inconclusive because one of the MFPs no longer existed. Further, deficiencies in the calibration process were noted. These observations led to the RMFPCE study.

OBJECTIVESThe primary objective of the RMFPCE study is to develop a calibration technique that quantifies and minimizes mass-flow measurement uncertainty of an MFP. This includes quantifying the effects of flow distortion, non-ideal geometric conditions, and the effect on uncertainty when applying the calibration of one MFP to a geometrically similar MFP which is often necessary due to time and cost constraints

APPROACHThe RMFPCE study is both experimental and numerical in nature. The experimental approach is to refine the calibration technique on smaller scale MFPs to minimize cost. Currently under investigation are the MFPs shown in Figure 1. The Boeing N+2 MFP was recently used in low-boom inlet tests in NASA GRC’s 8x6 ft SWT and elsewhere. The NASA GTX MFP is geometrically similar to many MFPs routinely used at NASA GRC for inlet testing. The tests are being conducted in test cell W6B at NASA GRC.

POC: David O. Davis (GRC) Figure 1. Typical Mass-Flow Plugs for Inlet Testing

RESULTSA numerical and experimental study of the Boeing N+2 MFP under undistorted and distorted flow conditions was recently completed and is being released as a NASA Contractor Report. Preliminary calibration of the GTX MFP over a range of Reynolds numbers under undistorted flow conditions has also been completed and results are currently under analysis.SIGNIFICANCEImproved assessment of inlet performance at the component level will lead to significant cost reductions by minimizing inlet changes at the vehicle level.

3.0” NASA GTX MFP

1.5” Boeing N+2 MFP


Combined Cycle Engine- Large Scale Inlet Mode Transition Experiment (Inter-Agency Agreement IA1-1207, Annex #3 Signed November, 2013)Agreement Partners: AFRL and NASA GRC

Task Objectives: Conduct Phase 3 test campaign in the GRC 10’x10’ Supersonic Wind Tunnel of the Combined Cycle Engine-Large Scale Inlet Mode Transition Experiment (CCE-LIMX) to demonstrate closed-loop control strategies for smooth and stable mode transition in preparation for Phase 4 testing

Milestone Due Date Exit Criteria/Comments

Analyze phase 2 data and develop control algorithms Nov.

2014Control algorithm developed, & tested in

simulation, c o m p l e t e d

Refurbish CCE rig and install into 10X10 Mar.

2015Test readiness review with actions completed,

c o m p l e t e d

Conduct phase 3 testing: Closed loop controlled mode transition

April2015

Demonstrate closed-loop mode transition in 10x10 SWT

Final analysis and report Sept. 2015

Closed-loop controls report approved for publication

Current Schedule: Due Dates now reflect receipt of initial funds on 2/28/14

Status/Issues: (Mar. 2015)• Research Readiness Review held on 2/26/2015. Test readiness review held 3/31/2015.• Test article hardware installation completed on schedule. Electronic setup, check-out,

and calibration is nearly completed.• Biweekly CCE LIMX team meetings (including AFRL reps) continue to be conducted.• Additional funding arrived to address secondary objective: develop engine integration

strategies. The additional testing is termed phase 3b. Phase 3b funding received by GRC in early January, 2015.

Project POC: LTN/Paul Bartolotta 3-3338Technical POCs: LTN/Dave Saunders (3-6278) and LCC/Tom Stueber (3-2218)10x10 Facility POCs: FT/Christine Pastor-Barsi (3-3867) and FTA/Julius Giriunas (3-3794) GTechnical Schedule ResourcesG G






Outline


3D CPR-Based Navier-Stokes Code

PROBLEMCurrent industrial CFD codes used for solving aeropropulsion flows with complex geometries generally use unstructured finite-volume methods and are typically no higher than second-order accurate. These methods constrain the accuracy and efficiency of current CFD codes.

OBJECTIVESDevelop a high-order 3D CFD code based on the CPR method for solving the Navier-Stokes equations on brick element meshes to demonstrate accuracy and efficiency improvements over standard methods.

SIGNIFICANCEThis 3D Navier-Stokes code uses the CPR method to efficiently compute high-order solutions on brick element meshes. Its capabilities are being extended to allow for hybrid element meshes and more generalized aeropropulsion-oriented flows.

POC: Seth Spiegel; TM: Jim DeBonis (GRC)

APPROACHThe CPR method provides a simple, efficient, and easy to implement

method for solving fluid flow problems on mixed element unstructured grids and is accurate to an arbitrary order. This method is the basis for a new CFD code for future use towards solving aeropropulsion flows with complex geometries. This code has been expanded from 2D inviscid flows to 3D viscous flows on brick elements. While extending the 2D CPR code to 3D, additional infrastructure has been embedded within the code to easily allow for future additions such as 3D hybrid meshes and non-uniform P-adaptive meshes.

RESULTSSimulation results of Mach 0.1 laminar flow over a flat plate with a freestream Reynolds number of 2.0×106 are presented in the included figures. This test case was used to validate the 3D Navier-Stokes solver because it has a known analytical solution given by the Blasius equation. These results favorably compare a 2nd order CPR solution with the analytical Blasius solution for both the streamwise velocity at the outflow boundary and for the skin friction coefficient along the solid wall.

Comparison of solution profiles from the CPR code with the analytical Blasius solution.

(b) Skin friction coefficient along plate(a) Outflow profile of streamwise velocity

-Transformational Tools & Technologies (T3) Project

Milestones FY14 FY15 FY16 FY17 FY18

2D CPR-based Euler code developed for mixed element meshes

Develop 3D CPR-based viscous code w/brick elements

Extend 3D CPR-based viscous code to mixed elements

Validate and document 3D CPR-based code

Incorporate implicit time stepping in to 3D CPR-based code

CPR-based flow solver for propulsion flows available for release


“Standard” Test Cases for Turbulence Modeling

PROBLEMThe Revolutionary Computational Aerosciences (RCA) Technical Challenge seeks to reduce error in turbulent flow simulations by 40%. A universally accepted set of standard test cases for turbulent separated flows, free shear flows and shock boundary-layer interactions has yet to be defined.

SIGNIFICANCE• Enables quantitative measure of CFD prediction method improvements• Highlights deficiencies in current models and guides additional canonical

experiments.• Invited presentation is scheduled for the AIAA SciTech 2015.

POC: Chris Rumsey (LaRC) / Jim DeBonis (GRC)

Shock/BL Interaction for Axisymmetric Compression Corner

APPROACHHigh quality datasets illustrating current deficiencies in CFD predictions of turbulent flows

were sought. Candidate cases were identified through extensive literature searches, past validation exercises and discussions within the aerospace community. Quantifiable metrics for measuring prediction improvements are defined.

Separation and Reattachment Locations for NASA 2D Hump

Centerline Velocity Profiles for NASA M=0.9 Cold Jet

FY14 Milestones/Accomplishments • Define "Standard" test cases for measuring

progress toward Technical Challenge, 9/30/2014.

• COMPLETE - Test cases defined:• NASA 2D hump• Axisymmetric transonic bump• 2D shear layer• Axisymmetric jet• Axisymmetric compression corner



Shock Wave Boundary Layer Interaction

• J. Brown et al, NASA Ames• Axisymmetric compression corner• Mach 2.85• 30 deg. conical flare• Data

– LDV• Mean velocities• Reynolds stresses

– Surface static pressures– Interferometry– Schlieren

- Dunagan, S.E., Brown, J.L. and Miles, J.B. ,” Interferometric Data for a Shock/Wave Boundary-Layer Interaction,” NASA TM 88227, Sept. 1986.- Brown, J.D., Brown, J.L. and Kussoy, M.I., “A Documentations of Two- and Three-Dimensional Shock-Separated Turbulent Boundary Layers,” NASA TM 101008, July, 1988.- *Settles, G.S., and Dodson, L.J., “Hypersonic Shock/Boundary-Layer Interaction Database NASA CR 177577, April 1991- Wideman, J., Brown, J., Miles, J., and Ozcan, O., “Surface Documentation of a 3-D Supersonic Shock-Wave/Boundary-Layer Interaction,” NASA TM 108824, 1994

*primary data source-Transformational Tools & Technologies (T3) Project


Shock Wave Boundary Layer Interaction

• Objective: Improve the prediction of shock boundary layer interaction including the extent of separation and the Reynolds stresses

• Metrics– Separation and reattachment locations, and separation length – Surface pressure coefficient– Velocity profiles– Reynolds stress profiles

• Rationale for– Simple geometry– Absence of corner flows found in many SWBLI experiments– Reynolds stresses available

• Rationale against– Separation onset and pressure distributions are already well predicted by some

RANS models– Cusped nose of model not defined; effect is assumed negligible



Informing Turbulence Models Using ILES

PROBLEMAccurate prediction of shock wave/boundary-layer interaction (SBLI) remains a challenge using the current industry-standard turbulence models. This is largely due to the lack of understanding of SBLI characteristics like low-frequency motion of the shock-separation system, three-dimensionality, and corner separation where the Boussinesq approximation starts becoming suspect.

OBJECTIVESUsing the insights provided by Implicit LES (ILES) in the physics of low-frequency shock-separation oscillations, three-dimensionality, and corner separation, inform the current turbulence models to gain improved predictions and/or show the need for development of new higher order turbulence models.

SIGNIFICANCEThis two-pronged approach will provide physical insights on the role that unsteadiness and three-dimensionality play in SBLI and lead to improvements in our current models and spur the development of new models that incorporate the relevant flow physics.

POC: Manan Vyas (GRC)

APPROACHHighly-resolved meshes will be used in SBLI simulations performed with ILES to, first, acquire

statistical quantities to study the unsteady characteristic of an SBLI and second, to calculate budget of exact equations of turbulence kinetic energy (TKE), rate of dissipation, specific rate of dissipation, and stress transport and compare with their RANS counterparts. An 8-degree SBLI exhibiting two-dimensionality will be investigated first and later a 9.5-degree SBLI with evidence of three-dimensional shock-separation system will be investigated. Effect of corner separation will be explored by including a sidewall in the latter simulation.

DETAILS OF PRELIMINARY WORKPreliminary simulations using a flatplate are currently underway. These simulations will help verify the suitability of turbulent boundary-layer generation for the present flow conditions and calculation of components of the budget terms like production, transport, dissipation, dilatation, etc. The code, FDL3DI, was used in the past for studies focusing on development of turbulent boundary layer using body-force based method and investigating shock unsteadiness in a different configuration. It employs bandwidth and order optimized WENO with Roe scheme for inviscid flux and a sixth-order compact scheme for the viscous fluxes. The time integration will be performed using implicit Beam-Warming scheme.

Current industry standard in(8o) SBLI RANS predictions-Transformational Tools & Technologies

(T3) Project






Outline


Turbulence CFD Validation Experiments (TCFDVE)

POC: David O. Davis (GRC) 17cm Axisymmetric Supersonic Wind Tunnel

PROBLEMVery few Shock Wave/Boundary-Layer Interaction (SWBLI) experiments reported in the open literature meet the rigorous criteria required to be considered as a CFD validation dataset. This is particularly true for experiments with detailed turbulence measurements.

OBJECTIVESObtain mean and turbulence quantities through a M=2.5 SWBLI of sufficient quantity and quality to be considered as a CFD validation dataset. Initial efforts will focus on a Mach 2.5 2-D (in the mean) interaction with follow-on efforts investigating 3-D interactions. Both attached and separated interactions will be considered.

APPROACHA new M=2.5 17cm axisymmetric facility has been constructed to investigate SWBLIs. The facility is located in Test Cell W6B at NASA GRC. The SWBLI is generated by a cone-cylinder located on the centerline of the facility. The strength of the interaction is varied by changing the cone angle. The measurement region of interest is where the conical shock interacts with the naturally occurring facility boundary-layer that is highlighted by the box shown in Figure 1. The new facility will be instrumented with conventional pressure instrumentation as well as hot-wire anemometry for measurement of turbulence quantities. Non-intrusive optical techniques such as PIV will be incorporated in the future. Test are also planned with dynamic surface shear film and fast response Pressure Sensitive Paint (PSP) in collaboration with Innovative Scientific Solutions, Incorporated (ISSI).

RESULTSThe basic components of the facility are complete and testing is underway. Preliminary characterization of the clean tunnel flow and two interaction conditions were completed on 4/2/2015.SIGNIFICANCEThe data to be generated has been previously unavailable. Further, development of an in-house capability to investigate SWBLIs will allow CFD code developers and turbulence modelers to have direct input into the experiment. It will also allow the ability to revisit measurements if deemed necessary.


22NASAAeronautics Research Your Title Here

Documents

1 Overview of NASA GRC’s Efforts In SWBLI 8 th Annual SWBLI Technical Interchange Meeting Mary Jo Long-Davis NASA Glenn Research Center Chief, Inlets and