Design, Fabrication, and Realization of a Supersonic Wind Tunnel for Educational Purposes

The supersonic wind tunnel is an indispensable facility for basic education in any course that covers compressible flows and one of the main pillars of any aerodynamic laboratory. The introduction of a supersonic wind tunnel at the aerodynamics laboratory of the Aerospace Engineering Department at Cairo University had often been postponed and was hindered by a lack of funds for the purchase of foreign equipment and expertise. Thoughts therefore turned to building such facility instead of buying it, substituting high-tech and complex foreign equipment for locally produced equipment, and ‘thinking out of the box’ to make the most use of available resources, even when this led to some unconventional applications. An extensive scheme for the design, fabrication, and realization of a multi-Mach number ( M = 1.5, 2, and 2.5) supersonic wind tunnel for laboratory experiments is proposed in this paper. The proposed scheme is simple, detailed and multi-level; it starts by utilizing one-dimensional isentropic flow theory for the conceptual design phase and makes full use of computational fluid dynamics at the detailed design phase. This ensured that we had a working design before we embarked on the manufacture of any components, which would have been costly to modify had there been any design error. A parametric study has been carried out for a number of design parameters, using numerical simulations. After the design and fabrication, a number of successful standard textbook experiments, for Mach number 2, were carried out as validation for the proposed scheme. The results showed good agreement with the theoretical predictions.