CASE STUDIES

a taste of what flightstream® can achieve

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D8 BOUNDARY LAYER INGESTION

Validations include the unpowered and powered configurations of the Aurora Flight Sciences D8 vehicle extensively tested by NASA/MIT. The FlightStream BLI analysis is validated against experimental data from NASA wind tunnels for a variety of incidence angles.

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NASA LEAPTECH WING

The NASA Leading Edge Asynchronous Propeller Technology (LEAPTECH) wing is one of several propeller-slipstream validation geometries for FlightStream. This configuration includes 18 propellers simulated using actuators discs in FlightStream in conjunction with a deployed flap and the associated wing slots modeled. The wingtip pods and the propeller spinner/nacelles are modeled with full accuracy using CAD models. The merge topology between these components is an important part of this validation study.

HIGH-LIFT PREDICTION WORKSHOP-3

The JAXA semi-span high lift configuration from the AIAA High-Lift Prediction Workshop-3 (HLPW-3) was tested in FlightStream and used to validate the software' ability to capture high-lift aerodynamic effects in the presence of realistic geometry components such as engine nacelles, pylons etc..

DRAG PREDICTION WORKSHOP-1

The AIAA Drag Prediction Workshop-1 (DPW-1) geometry was the DLR-F4 configuration. This geometry represents some of the earliest validation studies done with FlightStream for compressible flow conditions (Mach 0.6). The vehicle is still used in our repository for its well-documented experimental pressure measurements on the wing surface.

DRAG PREDICTION WORKSHOP-2

The AIAA Drag Prediction Workshop-2 (DPW-2) DLR-F6 configuration is a natural extension of the F4 configuration of the first workshop. This vehicle was tested at a higher Mach number (Mach 0.75) and tested in ONERA S2MA W.T. August 1990. This configuration is also used by the FlightStream team to verify the ability of the software to capture close-proximity nacelle-wing interactions.

GENERIC WING WITH FLAPS

This is one of the simpler validation cases for FlightStream. It is a typical regional turboprop wing planform, with an aspect ratio AR = 11 and a tapered outer panel. The idea is to use this wing as a baseline reference for later simulations on distributed electric propulsion configurations. Comparison of FlightStream predictions are made against RANS CFD simulations.

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NASA EET-AR-12

The NASA EET-AR-12 configuration shown here is the high-lift version. Wind tunnel data is available for both the cruise and high-lift versions of the configuration. Both of these vehicles are modeled in FlightStream and serves as a useful illustration of the ability of FlightStream to capture the lift, drag and moment variations associated with the deployment of high-lift devices.

NASA V/STOL TILT-WING

This NASA V/STOL tilt-wing configuration was tested at the NASA Langley 7x10 feet wind tunnels in the 1960s. The geometry is a very useful combination of powered-wing effects (slipstream), high-lift configuration (flaps deployed) and experimental data collected at very high incidences (0-90 Deg). It serves as a benchmark case for the physics behind the FlightStream implementation of the Conway propeller actuator model.

NACA TN-4117 ANNULAR AIRFOIL

NACA tested a series of different engine nacelle configurations in 1957, as documented in the TN-4117 report. These configurations varied on the basis of nacelle aspect ratios and measurements were done for the lift, drag and pitching moment characteristics. These nacelles were tested with FlightStream to verify the software ability to capture accurate aerodynamics for engine integration studies.

CESSNA-210 "NLF(1)-0414F WING"

The Cessna-210 with the NASA NLF(1)-0414F airfoil wing is a standard validation case for FlightStream®. A conventional, contemporary civilian aircraft, the NLF(1)-0414F airfoil is nevertheless an advanced airfoil design that sheds light on the ability of the FlightStream® solver to model the flow over advanced airfoil shapes.

PIPER PA-24

The Piper Pa-24 was tested at NASA Langley Research Center's Full-Scale Wind Tunnel, in 1969, and the results were presented in the technical report TN D-5700. These tests included both powered and un-powered flight. The Piper Pa-24 represents a standard validation model for FlightStream. The CAD model for the Piper Pa-24 was created by DARcorporation engineers. This validation study was performed by DARcorporation engineers early in 2017 to test FlightStream® ability to use its propeller actuators on a steady-state aircraft.

Unsteady Aerodynamics & Acoustics

FlightStream has advanced unsteady aerodynamics capabilities. As part of recent NASA-funded activities, FlightStream now also has the ability to perform computational aeroacoustics for early design UAM and other unconventional configurations! Learn more about our new new aeroacoustics capability.

NASA XC-142 V/STOL

The AIAA SciTech 2018 conference was held in January, 2018, in Kissimmee, Florida, USA. During this conference, Terrafugia and Research in Flight presented a validation study of the actuator models for steady-state propeller simulations in FlightStream®. This validation study was performed on the NASA XC-142 V/STOL geometry. Analysis results for the powered and unpowered test conditions were validated against wind-tunnel data for the XC-142 1/11-scale wind-tunnel.

TRANSONIC TRUSS-BRACED WING

The Subsonic Ultra Green Aircraft Research (SUGAR) TTBW aircraft is a Boeing N+3 aircraft configuration funded by NASA ARMD Advanced Air Transport Technologies (AATT) project. The TTBW flies at high subsonic and transonic flight conditions and presents a good validation for compressible flow effects in FlightStream. Mach 0.745 test data was used for this validation study.

DTIC SUBOFF HYDRODYNAMICS

The DTIC SUBOFF configuration is a hydrodynamic validation geometry for FlightStream. The ability of FlightStream to simulate both aerial and marine vehicles is validated with the SUBOFF geometry for a range of configurations: basic hull, hull-with-sail, hull-sail-fins, ducted propulsor etc. Validation data includes the vehicle surface pressure distributions and complete vehicle loads and moments at a range of vehicle attitudes.

NASA STARC-ABL

The NASA Single-Aisle Turboelectric Aircraft with Aft Boundary Layer (STARC-ABL) propulsion is a conventional single-aisle tube-and-wing configuration modified with a ducted, electrically-driven, boundary-layer ingesting tailcone propulsor (AIAA-2016-1027). This configuration is designed for Mach Numbers in the range of 0.7 to 0.785 and presents a useful compressible boundary layer validation study for FlightStream.

NASA N2A HYBRID-WING-BODY

Several wind tunnel studies have been conducted in recent years in order to better characterize the aerodynamics of the Hybrid Wing-Body configurations. One of these is an investigation conducted by NASA Langley on the low-speed aerodynamics of the N2A, a HWB configuration designed by the Boeing Company (modified from MIT’s SAX-40 configuration) to support the NASA Environmentally Responsible Aviation (ERA) Project.This study provides a great range of validation data to support the efficient computational aerodynamic prediction of HWB aircraft with FlightStream®.

Northrop YF-17

The Northrop YF-17 validation is used to test FlightStream ability to capture LERX vortices and their contributions to the delayed onset of stall at high-incidence flow conditions. Experimental data is available from NASA wind tunnel tests and includes both freestream and tunnel-interference conditions.

NASA AD-1 OBLIQUE WING

One of the more well-known NASA experimental aircraft is the AD-1 Oblique Wing test aircraft. A low-speed flight investigation for the AD-1 was performed in the 1980s with a focus on extracting force and moment coefficients and aeroelastic effects. The vehicle is reproduced here for FlightStream and the validation was performed agains this experimental data for a range of main wing obliqueness angles. The 60 Deg. oblique wing configuration is shown here.

GENERIC BOX-WING

This relatively simple box-wing configuration originally served as the precursor FlightStream validation performed by the researchers at the University of Aachen, Germany and RMIT, in 2018. The configuration employs a NACA 6-Series laminar airfoil, wing sweep and taper. This geometry serves as a simpler reference that preceded the NASA Joined-Wing Research Aircraft (JW-1) configuration validation performed with FlightStream. The geometry serves as a useful tutorial validation for new FlightStream users.

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NASA JOINED-WING AIRCRAFT

The NASA Joined Wing Research Aircraft (JWRA) was tested in the Ames Research Center wind tunnel facilities in the 1980s. The vehicle shown here (JW-1) was part of that study. The fuselage and propulsion is similar to the NASA AD-1 flight vehicle and was also validated in FlightStream. The JW-1 and its sister configurations were validated in FlightStream for a range of vehicle attitudes and configuration changes. Joined wings are rapidly gaining interest for emerging vehicles in the 21st century.

NREL 10MW WIND TURBINE

The NREL 10 MegaWatt Horizontal Axis Wind Turbine (HAWT) was tested in FlightStream using both the axisymmetric rotary solver (steady-state) and the full unsteady solver with non-symmetric wind profiles, gusts atmospheric boundary layer profiles. Comparison data is relative to RANS CFD simulations.

NASA GENERIC T-TAIL

The NASA/Boeing Generic T-Tail (GTT) was tested in the 12 ft. LST and NAART tests. Experimental validation data for FlightStream includes static and dynamic derivatives, basic aerodynamic loads and moments, as well as control surface deflection loads.