Experimental Investigation of Liquid and Gas Fueled Flames Towards the Development of a Burning Rate Emulator (BRE) for Microgravity Applications

Abstract

Laminar steady burning on flat plates was studied at various orientations with respect to gravity. Flat wicks were saturated with methanol or ethanol. Steady flames were obtained, and ranged from boundary layer flames to plume-type burning. Maximum burning rate per unit area was recorded at an upward inclination of 30º. Mass flux decreased with increasing wick length for all orientations. Dimensionless correlations, using a Rayleigh number and the orientation angle, collapsed most of the data, but not for the horizontal and vertical cases. The measured heat flux correlated with expected averages based on burning rate data; theoretical results were similar but radiation likely affected the wicks results. Gas burner flame stand-off distances when emulating methanol flames were in reasonable agreement, showing similarities in laminar, onset of turbulent flow, and boundary layer separation. 0g ethanol wick flames from drop tower testing and airplane testing are shown.