Improvement of contact methods of heat-flux measurement

A technique is described for determining local values of heat-flux density from jets of heated gas to a specially designed calorimetric probe. Results are presented for an application of this technique under conditions characteristic of a free-air plasma jet. For comparison purposes, results are also given which were obtained under the same conditions using several other well-known techniques. It is shown that plasma parameters (temperature, enthalpy) can be derived directly from heat-flux density values recorded by an unsteady-state calorimeter (a detector with a linear characteristic or a dynamic thermocouple) placed in a plasma jet, provided the coefficient of heat transfer from the jet to the probe is known.