The Effect of Wire Length and Separation on X-Array Hot-Wire Anemometer Measurements

This paper describes a simple method for the calculation of errors due to the finite length and separation of X-array hot-wire anemometers. Results of computations for a typical wire array are presented for total and spectral turbulence measurements. Although the actual errors are slightly underestimated due to the simplifying assumptions used to reduce the computational effort, it is found that the wire length and separation effect is very significant. The analysis does not require complete correlation or spectral functions of the flow and includes the effect of nonuniform wire sensitivity.