Some checks of Taylor's hypothesis in a slightly heated turbulent circular jet

Taylor's hypothesis has been examined by comparing temporal variations of the temperature fluctuation θ with the corresponding spatial variations. The comparison is made on the axis of a circular jet in the self-preserving region of the flow for streamwise separations extending to about 10 Kolmogorov microscales. The use of the hypothesis yields reliable estimates of streamwise temperature correlations and also of second- and third-order moments of streamwise temperature increments. Fourth-order moments of these increments are estimated less accurately. Departures from the hypothesis are smaller than in the plane jet; consistently, local isotropy appears to be more closely satisfied in the circular jet.