LENS Facilities and Experimental Studies to Evaluate the Modeling of Boundary Layer Transition, Shock/Boundary Layer Interaction, Real Gas, Radiation and Plasma Phenomena in Contemporary CFD Codes.

摘要

We operate five tunnels in the LENS supersonic and hypersonic ground test facility complex. The 48- inch shock tunnel was constructed in 1958 and represented one of the first facilities of its kind constructed to perform government and commercial testing at Mach numbers from 6 to 20. This facility has been used extensively to produce high-quality measurements in high Mach number, low Reynolds number flows where viscous interaction and rarefied gas phenomena are important. It has been used in the early capsule and space shuttle programs for NASA to collect design data for these systems. In the 50 years since it has been constructed, it has also been used in many studies to evaluate and improve the prediction methods used to design hypersonic vehicles. The LENS I facility was constructed in 1992 and used initially in programs to evaluate the aerothermal and aero-optical performance of hypersonic interceptors. Since then, it has been used in many studies to evaluate the aerothermal characteristics of re-entry vehicles and provide code validation data. The LENS II facility can be operated as a shock tunnel, Ludweig tube and expansion tunnel. At the low Mach number end, it provides the capability to generate Reynolds numbers of the order of a billion while large-scale testing of full-scale hypersonic vehicles can be conducted at duplicated flight conditions up to Mach numbers of 10. With additional components, the LENS II tunnel can operate as an expansion tunnel which can generate velocities of up to 20,000 ft/s. This facility was used as a prototype for the LENS XX facility which can operate with a hydrogen driver at higher pressure and temperature conditions to reach velocities of up to 30,000 ft/s. Figure 1 shows the velocity altitude capability of the LENS facilities and a list of hypersonic vehicles which, with the exception of Orbiter and Apollo capsule, have been tested at full-scale fully duplicated flight conditions.