Heat transfer evaluation of a HVOF combustor under several operating parameters with interest in plasma production for future MHD channel analysis

摘要

Researchers at the National Energy Technology Laboratory are performing a series of experiments using a high velocity oxy-fuel (HVOF) system to generate a weakly ionized supersonic plasma source. Such sources are of interest to be coupled with magnetohydrodynamic systems for electrical power extraction. The HVOF operation is studied spanning a wide range of operating parameters (130 KW ≤ Q_(thermal) ≤ 188 KW, 0.77 ≤Φ≤ 1.39). The thermal power transferred across the combustion chamber, convergent-divergent (C/D) nozzle, and barrel walls is determined using a calorimetric measurement method. Irradiance from the HVOF exit plume is measured using a wide-angle broad band radiometer. Radiance measurements are obtained using an IR camera fitted with CO_2 filter in order to measure the plume's morphology under various operating parameters. The heat transfer measurements are compared to CFD modeling results of the HVOF experiments. These simulations are performed using customized version of sonicParcelFoam from the OpenFOAM library. The model results largely trend with the experimental results as combustion conditions are varied, with some differences noted. The overall HVOF heat balance information can be used to identify the enthalpy available within the gas flow to decompose the potassium carbonate seed and create the weakly ionized plasma source.