High Pressure Gas Facility

The High Pressure Gas Facility at Hessert Center features twin two-stage, intercooled air compressors, a twin-tower regenerative gas dryer and three large air storage tanks which provide the capability of storing 12,000 cubic feet of dry, filtered air at pressures up to 280 psi. Precise control of mass flowrate for each test is achieved by means of a high flow rate stagnation pressure control valve. One configuration utilizes a two-dimensional converging-diverging nozzle in order to achieve a design exit Mach number of 1.5. The nozzle discharges into a rectangular test section 1.5 m in length where a fully turbulent, nominally zero pressure gradient boundary layer is allowed to grow before encountering either a compression ramp or concave wall model where measurements of the resulting shock wave/turbulent boundary layer interaction are made. Optical glass sidewalls allow visualization of the boundary layer/shock interaction by means of either Schlieren or spark-shadowgraph technique. Flush mounted wall pressure taps allow the wall pressure distribution to be continuously monitored during tests. Hot-wire and hot-film probes specifically designed for use in supersonic flow are used in conjunction with special high frequency bridges. Probe positioning is to be accomplished by a precision three axis traverse driven by stepper motors. A dedicated Masscomp 5550 computer system is used for computer monitoring and control of the facility, probe positioning and extremely high speed, multi-channel, on-line digital data acquisition, storage and post processing.

A new, 500 psi facility is currently under construction. Once completed, it will allow experiments to be performed with exit Mach numbers as high as 2.50.

Direct comments, questions, and corrections to amedept@nd.edu