Mixed and Dynamic Response of Hot Wires and Cold Wires and Measurements of Turbulence Statistics

Abstract

Hot wires respond to temperature as well as to velocity, whereas cold wires respond to velocity as well as to temperature. The static and dynamic response characteristics are summarized and it is shown that the frequency transfer functions for the four different responses in general are different. The influence of the transfer characteristics on measurements of turbulence statistics is discussed; it is shown that the nonideal response behavior influences, most strongly, statistics involving the correlation between velocity and temperature and here, most seriously, parameters involving small-scale turbulence.