Planar Subsonic Jet Facility

The Planar Subsonic Jet Facility at Hessert Center is a very low turbulence open circuit jet flow field facility. It is powered by a centrifugal blower, which supplies air to a plenum chamber. The blower and plenum are coupled by means of a flexible duct, which provides excellent vibration isolation. A carefully designed and tested rectangular duct containing flow straighteners and turbulence reducing screens of various mesh sizes leads the flow from the plenum to the nozzle assembly. The two-dimensional nozzle is of cubic contour with zero derivative end conditions and was constructed from aircraft foam, which was then laminated with an acrylic material in order to achieve an extremely smooth and polished finish. The nozzle has a contraction ratio of 22 to 1 and ends in a slot that is 1.27 cm wide and 45.7 cm in height. The flow field is bounded by two large horizontal confining plates separated by a 0.457 m air gap which serves to keep the base flow two-dimensional in nature. The facility is capable of providing exit turbulence intensities as low as 0.01% over a wide range of exit Reynolds numbers. A precision traversing mechanism is attached which allows for precise hot-wire probe positioning in three-dimensions. This unique facility is complemented by a MicroStar Laboratories simultaneous sample-and-hold boards. The system allows one to sample up to 512 channels simultaneously. Gateway 2000 computer with Pentium Pro 200 processor is utilized for facility control and monitoring, probe positioning, on-line digital data acquisition and processing as well as graphic data display.

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