HEAT-TRANSFER ANALYSIS OF A PLUG-TYPE HEAT-FLUX GAUGE

An analysis of a miniature plug-type heat flux gauge is presented. The analysis provides previously unavailable quantitative details of the heat transfer within this gauge type. The analysis is performed using a two-dimensional, axisymmetric numerical model with temperature-depen dent thermal properties. The model is solved using the alternating dir ection implicit finite difference solution procedure. Details of the c omparison of the model results with experimental data are presented. I sotherms, gauge centerline temperature distributions, and heat fluxes computed at various locations within the gauge are presented and discu ssed. For the cases studied, the numerical analysis reveals that the m easured heat flux indicated by the gauge is not the same as the heat f lux at the gauge hot active surface. Using temperatures measured by th e gauge as input, the numerical model enables one to compute the heat flux into the surface in which the gauge is mounted, at positions that are thermally undisturbed by the presence of the gauge. This can be d one regardless of whether or not the heat flux at the gauge hot active surface is the same as the heat nux into thermally undisturbed portio ns of the surface.