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References and reviewers were identified at the SciTech meeting. Each reviewer should use this form – hand or type written – to capture info as a document is reviewed.
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Send completed reviews to Steve Dunn at steven.c.dunn@nasa.gov
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Reviewer: __CASTNER__________________________________
Reference Document Title: _Wind Tunnel Testing’s Future: A Vision of the Next Generation of Wind
Tunnel Test Requirements and Facilities AIAA 2010-142 ___________________________
Date of Review: _7-7-2015_______________
Please fill in each topic area, as applicable (add space as needed):
I.
Vision for Experimental Fluid Dynamics – Ground (and Flight, as mentioned) Testing a.
List/describe future technologies/configurations in terms of Expected/Projected Needs
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Improvements in speed and accuracy of computational simulation.
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Highly integrated simulation and wind tunnel testing
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Rapid development of wind tunnel model hardware
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Wind tunnel facilities capable of rapid evaluation of on- and of-body flow physics for identified configurations for a broad range of test types and speed ranges. b.
What capabilities will be needed and how will they need to work and be managed?
1.
“Development of a knowledgeable test workforce is critical for the national infrastructure.”
2.
“Improved test technology is crucial to enabling future system development.”
3.
“Maintenance and improvement of key test assets is a vital component of enabling future test capabilities.”
4.
“Divestment of redundant and nonessential test infrastructure is required to focus limited resources on critical capabilities and new infrastructure requirements.”
5.
“New high-speed test infrastructure is required to meet anticipated requirements for future systems.” c.
Integration of CFD and Ground/Flight Testing (includes risk management during research and product development)
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It is expected that future programs will rely on highly integrated computational simulation and physical modeling in the wind tunnel. The most ideal future scenario will include highly integrated computational and physical simulation capable of rapid evaluation of concepts and configurations. Robust and reliable CFD modeling simulation will be used to evaluate and narrow the design options to a chosen few. Rapid wind tunnel model design and fabrication would begin taking advantage of light-weight, easily workable, and high-strength materials to manufacture modularized model parts for testing. Wind tunnels would be readily available with capabilities spanning a large speed range and flow visualization at any speed, efficient data gathering process (hardware and software), automation that reduces model changes, and adaptable to various types of testing, i.e., aero, propulsion, loads, and noise. Entries in the tunnel will be shorter and more rapid, providing focused physical validation of analytic estimates and, where appropriate, volumes of data required for extensive control law and flight envelope expansion. d.
Grand Challenge Problems
As wind tunnel facilities and capabilities decrease and test costs almost certainly increase, programs become forced to choose between accepting increased vehicle development risk through limited testing, utilizing foreign test assets, or forgoing testing altogether and committing to full dependency on computational modeling. These alternate scenarios present potential risks of significant design issues and flight failures that can be costly and time consuming to rectify.
II.
Current State of EFD a.
Performance/Benchmark – types of capabilities/test techniques, where it works best, best practices, how do we know
Within the aerospace community, wind tunnel testing will continue to be utilized to validate predictions, populate databases, and provide an anchor point for baseline concepts. Figure 7 shows the anticipated impact of CFD on overall major-program wind tunnel testing requirements. CFD will increasingly complement wind tunnel data acquisition requirements.
It should be noted that wind tunnel testing will be a fundamental aspect of vehicle development and will continue to be so for the foreseeable future. As stated in the 2005
Institute for Defense Analysis (IDA) Science & Technology Policy Institute, “Review of CFD
Capabilities,”10 “Assuming computing power follows historical trend lines, complete aircraft design database generation using CFD is still 40+ years off.”
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Rev 4/2/15 b.
Capabilities i.
Mission area(s) Performance Availability (strengths and weaknesses associated with condition, investments, capability sustainment, reliability, customer focus/satisfaction)
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High-speed testing for transonic transports to hypersonic vehicles: Facilities to test transports, high-altitude ISR, and time-critical-to-target platforms are reaching critical mass; and they are in need of major upgrades or maintenance to continue operation. In addition, to answer the government’s challenge of advancing our technology to reduce energy consumption, reduce noise impact, and improve vehicle performance, these major tunnel facilities will need to support non-traditional concept entries requiring unique or innovative test methodology.
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Low Reynolds number (Rn) micro UAV flight (ultra low turbulence) simulation: Adequate tunnel facilities are still available to address normal low-speed testing. The Air Force Research Laboratory’s “challenge growth initiative”11 may be the venue to address wind tunnel test needs for nano and micro UAVs.
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Unsteady aerodynamic testing for flapping wing.
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Urban flow, large-turbulence testing for micro vehicles and hybrid airships.
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Stratospheric test capability ranging in Mach numbers from 0.5 to 2.5, Rn/ft up to 5 million, dynamic pressures up to 1500 psf and simulating altitudes
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 up to 80,000 ft are required.
Low Rn, ultra-low-turbulence flow for ISR platform testing.
High Rn low-turbulence flow for high-speed platforms. ii.
Staffing and knowledge management
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Rev 4/2/15 c.
Integration i.
Computational methods
1.
Maturation of computational processes
2.
How GT techniques and processes must evolve to support integration ii.
Support to flight testing iii.
Measurement and instrumentation technologies maturation, including teaming to define needs to measurement developers and producers (again, integrated with CFD and flight test)
Wind tunnel testing today also focuses on more diverse data for a baseline concept that can include force and moment data, pressure data, hinge moments, on- and off-body flow field surveys, and noise surveys for source detection. iv.
Government and industry development, proprietary versus open source
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III.
EFD/Ground Testing Technology Gaps and Impediments a.
[Note: This is likely a work product from assessing the first two sections. Included to capture anything already identified in the references.]
IV.
Technology Development Plan a.
[Address the gaps – include anything already identified in the references.]
There will be additional info that doesn’t fit into the above categories and we still need to capture that and then figure out how it fits into our paper. The following is a start at some of this potential info.
V.
Internal and External Environments
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VI.
Needs and Capabilities (not covered above)
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