Fluid flow modeling in a gas-filled optical cell [articol]

Abstract

This paper presents a modelling investigation of the recirculating nitrogen gas flows present in an optical cell containing an incandescent filament. The free convective fluid flows are driven by the hot filament located centrally in the cylindrical cell; gas temperatures range from 380 K in wall regions to 2700 K at the filament. The fluid physical properties are temperature dependent. The model equations of continuity, Navier-Stokes and energy are numerically solved with a finite volume method. The obtained results show that the thermal and velocity fields have three-dimensional flow characters. Strong convective effects are observed around the filament ends, where the highest temperature gradients are found. The study demonstrates the end effects on the temperature distribution and fluid flow.