07 - Systems, Subsystems and Equipment
AERODYNAMIC DESIGN METHODOLOGY OF A NON-UNIFORM PERFORATED INVERSE CONICAL FLOW SPREADER IN INTERMITTENT BLOW DOWN WIND TUNNEL
Q.-H. Nghiem¹, T.-G. Nguyen¹, B.-M. Pham¹, P.-M. Nguyen¹; ¹Viettel Aerospace Institute, Vietnam
This study presents the aerodynamic design method of the non-uniform perforated inverse conical flow spreader (non-uniform PICFS) used in intermittent blowdown wind tunnel. This device, which is installed inside the wind tunnel’s plenum chamber, is to slow down and to spread uniformly flow coming from the inlet pipe by tearing apart it into many small jets and letting those jets coalesce. However, despite widely being described in various documents, there has been no overall design guideline so far mentioning PICFS design variables, for example, hole sizes, number of holes and perforation uniformity. This study discovers that at least for square inlet pipe shape, a non-uniformly perforated device offers superior downstream flow uniformity to that of a uniformly perforated one. Therefore, the design process has been proposed to obtain improved freestream velocity distortion at the plane finding at one plenum chamber’s diameter downstream of the flow spreader.