Published online by Cambridge University Press: 04 July 2016
The advantages of using heavy gases in wind tunnels—reduced power consumption and scale size — have been appreciated for some time. To be sure of correct scaling of the results from such a tunnel, the working fluid should have a specific-heat-ratio γ equal to that of air (γ = 1·4); such a fluid can be obtained as a mixture of a monatomic gas with a polyatomic one. Here, general principles for choosing such a mixture are discussed, and estimates are given for the savings in size and scale which may be expected (compared to a conventional tunnel), following earlier work of Chapman.
Present address: Department of Physics, Brunel University, Uxbridge, Middlesex.