Magneto-fluid-mechanic heat transfer from hot film probes

An experimental study of thermally induced convection of molten gallium in magnetic fields

“…However, as long as the probe induced natural convection is not important it can be assumed the magnetic field will not affect the hot-film probe. Lykoudis and Dunn [29] calibrated hot-film probes in mercury over a Reynolds number range of 0-130 and Hartmann number range from 0 to 4.68. They found that the cubic root criterion suggested by Collis and Williams [30] predicts the critical Reynolds number between the free and forced convection regions well.…”

“…Therefore, the effect of probe induced natural convection can be neglected except for velocities below 0.2 cm/s. At the low velocities the magnetic field could alter the probe induced natural convection flow and therefore the heat transfer from the probe [27][28][29]. Since the purpose of the work is to investigate the effect of a magnetic field on natural convection, it is difficult to predict a priori when this effect will be important.…”

Experimental investigation of the origin of residual disturbances in turbulent MHD flows after laminarization

“…For the hot-film measurements we used the cylindrical quartz-coated probes which seem to be favoured by most experimenters (Hill 1968;Hoff 1969;Malcolm 1969Malcolm , 1970.…”

“…Several correction procedures have been proposed in the literature (Sajben 1965 ;Malcolm 1969;Hill 1968;Hoff 1969), in order to deal with the first aspect. For turbulence-intensity measurements, however, since any change in the sensor sensitivity is reflected to the same extent in both the fluctuating velocity and the average velocity, such corrections are not necessary, provided a linear voltagevelocity dependence is obtained a t the output of the anemometric system.…”

“…According t o Lykoudis & Dunn (1973) for the flow parameters in our investigation (Hartmann number related to the sensor between 0 and 1, Grashof number based on the sensor diameter equal t o 0-3 and interaction parameter of the order of no magnetic-field influence is to be expected on the heat transfer from the sensor. Except during the cross-correlation measurements, the sensor of the hot-film probe was directed along the magnetic-field lines.…”