Application of atomic layer thermopile (ALTP) sensors in organic vapor flows

Abstract

The applicability of hot-wire anemometry (HWA) and atomic layer thermopile sensors (ALTP) for flow measurements in high subsonic air and organic vapor flows was experimentally tested in a case study. Conventional hot-wire probes and an atomic layer thermopile sensor device were placed in free jets of air and the organic vapor Novec 649 which were established in a closed wind tunnel. The fluid Novec 649 consisted of heavy molecules, and it represented real gas flows. The impact of the high density of the organic vapor on the two measurement techniques was assessed. The maximum Mach number was about 0.7 in the experiments, and the turbulent spectra were obtained using the two measurement approaches. The outcome of the case study demonstrated that ALTP sensors can be useful devices for investigating high-speed flows of organic vapors. This makes this measurement approach interesting for aerodynamic investigations of cascades designed for organic Rankine cycle (ORC) turbines.