ON THE DEVELOPMENT OF HYPERSONIC TECHNOLOGIES FOR AERODYNAMIC RESEARCH AT HIGH REYNOLDS NUMBERS

摘要

Various ways of increasing the Reynolds number, Re, in hypersonic wind tunnels were considered. Numerical and analytical investigations aimed at evaluating various methods of increasing the Re number in wind tunnels were performed with allowance for real gas effects (nitrogen or air) on stagnation pressures, po, from 1 to 2000 MPa; stagnation temperatures, T_o, from 300 to 3000 K; and Mach numbers, M, from 5 to 30. The effects of flow overexpansion in the nozzle, some cost efficiency considerations, and worldwide experience in the development of industrial gas-dynamic and aerodynamic wind tunnels were considered. From the results obtained, it is concluded that the preferable way of solving the problem of increasing the Re number in wind tunnels is to increase the stagnation pressure of the test gas for nozzle exit diameters D = 1-1.5 m and test duration up to 1 s.