Thermal Property Determination of Gases Based on Temperature Oscillating Technique. An Investigation

摘要

Thermal conductivity and thermal diffusivity of fluids are a few of thermo-physical properties which characterize a fluid. Different methods have been developed in previous years for the measurement of these two properties, some of them are transient hot wire, 3ω and temperature oscillation technique. The current investigation is focused on temperature oscillation technique and had the scope of understanding the principle, its limitation and its applicability to an existing gas thermal flow sensor. The investigation consists of 1-D analytical and 3-D numerical model of the existing sensor. The investigation indicated a dependency of the measurement quantities on the thermal properties of the gases and the cause of the discrepancy between the theoretical and the real sensor model. Furthermore, quantities such as the temperature amplitude of the heater can be used for the measurement of thermal conductivity.