Mixing spray pipe runner wall face determination method, mixing spray pipe and supersonic speed mixing wind tunnel

The invention discloses a mixing spray pipe runner wall face determination method, a mixing spray pipe and a supersonic speed mixing wind tunnel. The mixing spray pipe runner wall face determination method includes following steps: providing a figure of an outlet section of a spray pipe to be determined and determining a circum-circle of the figure; taking the circum-circle as the outlet section of an imaginary round spray pipe, and determining a curve shaped surface of the round spray pipe by using a characteristics method; extracting filament line races of a runner according to the curve shaped surface of the round spray pipe; and determining filament lines in the filament line race corresponding to each point on the figure, wherein the filament lines of all points on the figure form a runner wall face of the spray pipe to be determined. According to the supersonic speed mixing wind tunnel, a three-dimensional mixing flow field is achieved, mixing efficiency is improved, quality of the flow field is comparable to quality of a two-dimensional flow field or an axisymmetric flow field, and a square outer spray pipe and a square experimental section facilitate implementation of observation technology.