The Engineering Sciences Center has the major laboratory responsibility for basic research and development in thermodynamics, fluid mechanics, aerodynamics, solid mechanics, and micro-mechanics. The Center combines computational modeling and simulation, analysis, and experimentation to solve complex problems of interest to Sandia, DOE, DOD, DHS, other government agencies, and industry.
The Center operates the Engineering Sciences Experimental Facility (ESEF) to provide experimental capabilities and advanced diagnostic methods for understanding the fundamental physics of complex fluid flow, heat transfer, aerodynamic systems, and the behavior of micro-devices. The ESEF is operated by a team of engineers and technologists in Building 865 in Tech Area I, which houses numerous thermal/fluids laboratories, laser diagnostic laboratories, two wind tunnels, and a high-altitude chamber. ESEF labs are located in additional facilities across Sandia, including the Micro Lab and in Tech Area III.
The ESEF is loosely divided into three groups of capabilities:
The Wind Tunnel Facilities
The Engineering Sciences Center is responsible for problems in aerodynamics associated with high-speed flight of missiles, re-entry vehicles, gravity bombs, satellites, and other aerospace vehicles. In support of this mission, the Center operates two wind tunnels: the Trisonic Wind Tunnel (TWT) and the Hypersonic Wind Tunnel (HWT), as well as the High-Altitude Chamber (HAC).
The Trisonic Wind Tunnel (TWT) facility operates at subsonic, transonic, and supersonic speeds for a wide variety of vehicles. The TWT traditionally is used for force and moment experiments to gain aerodynamic performance data for flight control systems, but is also used for understanding basic physics of high-speed flows and providing data for the development and validation of computational models. It is a blowdown-to-atmosphere facility with a 12-inch square test section that can produce subsonic and transonic flows in the test section by using a converging nozzle in conjunction with perforated test section walls. Supersonic conditions are achieved by using solid converging-diverging nozzle walls up to Mach 3. For further information, click here.
The Hypersonic Wind Tunnel (HWT) facility is a blowdown-to-vacuum facility capable of producing Mach 5, 8, or 14 flow past a model using either air or nitrogen as the working fluid. Each test section is 18 inches in diameter and has four glass windows placed 90 degrees apart from each other for visualization. Model hardware is normally sting-mounted and typically ranges in size from 6 to 20 inches long and a base diameter of 5 inches or less. For further information, click here.
Both wind tunnels employ a variety of diagnostics. This includes traditional aerodynamic instrumentation including 17 different internal strain-gage balances, surface pressure transducers, Pitot probes and rakes, heat transfer gages, and model spin testing. Optical diagnostics such as schlieren photography and high-speed imaging are commonly employed. The ESEF also has substantial expertise in advanced diagnostics that are routinely used in the wind tunnels, including Particle Image Velocimetry (PIV), Laser Doppler Velocimetry (LDV), Laser-Induced Fluorescence (LIF), Filtered Rayleigh Scattering (FRS), and Pressure Sensitive Paint (PSP). More diagnostics information is available here.
The High-Altitude Chamber (HAC) facility is actually part of the vacuum system used for the HWT facility, but may be isolated from the wind tunnels for testing flight articles at simulated altitudes up to 230,000 ft. The testing chamber is 27-ft in diameter and can accommodate articles up to 1 ton weight and 60 inch diameter. Additionally, a testing centrifuge can spin articles to 600 rpm. The HAC has been used for a wide variety of experiments which require low density conditions to simulate high altitude and exoatmospheric conditions. Common tests include the checkout of full-scale system hardware prior to launch; this includes ejection, inflation, and free-fall testing, and may involve explosive and pyrotechnic component testing for deployment. For further information, click here.
Experimental Thermal/Fluids Laboratories
The ESEF complex also contains several independent laboratories for experiments and advanced diagnostics in the fields of thermodynamics, heat transfer, fluid mechanics, multiphase flows, aerosols, and material decomposition. Our experimental research activities are focused on both advanced diagnostics and fundamental experiments. We seek to improve our understanding of phenomena in areas of fluid flow, heat transfer, and aerodynamics. We develop state-of-the-art diagnostic techniques for application to benchmark experiments aimed at understanding the fundamental nature of complex systems. This understanding is used to develop and validate the theoretical and computer models necessary for system design and analysis.
Micro-Scale Laboratories
Additional ESEF laboratories are part of Sandia’s MESA complex for work within microscale science and technology to develop and apply fluid and thermal transport capabilities that bridge the continuum to non-continuum regimes. A primary application area is to support the manufacture, design and qualification of microsystem-based components to meet Sandia needs. Advanced diagnostics similar to those used in other ESEF laboratories are employed for microsystem characterization.
For information regarding the Design, Evaluation & Test Technology Facility, click here.