Abstract
The behaviour of low-order moments of the temperature increment δθ ≡ θ(x + r) − θ(x) is considered, for both a range of flows and of the Taylor microscale Reynolds number Rλ. The focus is on values of the separation r which are either large compared to the integral length scale or lie within the inertial range. In the former case, the dependence on Rλ appears to be reasonably well predicted, provided the velocity/temperature time scale ratio is taken into account. In the latter case, the prediction, based on local isotropy, appears to be approached only at sufficiently large Rλ.