Measuring capabilities of conduction anemometers with a uniform external magnetic field

L. M. Korsunskii

Abstract
An analysis is made of the effect which the structure of the measured stream has on the readings of conduction anemometers with a uniform external magnetic field. It is established, as a result, that such instruments are suitable for quantitative determinations of the intensity of velocity fluctuations in isotropic streams or in streams perturbed only by two-dimensional eddies with streamlines parallel to the magnetic field. Measurements in anisotropic streams perturbed by three- dimensional eddies contain amplitude and frequency distortions which depend on the scale ratio of perturbations in various directions and which lead to ambiguous readings. In the measurement of two-dimensional eddies whose streamlines are perpendicular to the magnetic field, moreover, the sensitivity becomes negligibly low. It is found that only one half of a signal corresponds to the measured velocity component and, therefore, conduction anemometers with a uniform external magnetic field are not suitable for analyzing the structure of turbulent streams, a structure defined by correlation tensors of various ranks.