Volumetric Heat Flux Characterization Experiments in the Interaction Heating Facility at NASA Ames

Abstract

Characterization of plasma flow conditions is an important link for any material test performed inside the Interaction Heating Facility (IHF) at NASA Ames Research Center. In a recent arc jet test campaign titled IHF 212, a series of sensors was deployed to study the volumetric heat flux distribution with the goal of improving the facility’s current ability to measure heat flux and to help understand physical phenomena through comparison with computational fluid dynamics. Further, potential asymmetry in the flow could be studied. In the test series, a pitot probe and a null point calorimeter were traversed across the arc jet flow stream; and a hemispherical slug calorimeter was used in a stagnation test configuration to give an additional data point at centerline. In addition, two 20° blunt-nosed, water-cooled, copper wedge assemblies, each holding ten slug calorimeters, were used to obtain shear flow heat flux measurements. Tests were conducted at facility maximum and minimum power settings. The shear flow heat flux measurements reveal a region of higher heat flux towards the West end of the facility by up to 9%. The heat flux data from the null point calorimeter sweeps show the same bias with the peak heat flux located 1.5 cm ± 0.5 cm from the centerline position. The pressure data from the pitot probe sweeps adds a third corroboration of the same observation as its peak is also towards the West end of the facility.