DETERMINATION OF GAS-SPECIFIC PARAMETERS FROM HEAT TRANSFER IN THE TEMPERATURE JUMP REGIME

摘要

A method for determining a gas-specific parameter (Hρ; WI; c_pρ) of a gas, in particular, a combustion-related parameter, uses a sensor element (10) comprising two structures for causing heat transfer through the gas, the structures having different dimensions (d1, d2) across which the heat transfer is effected. The method comprises operating the sensor element (10) to cause heat transfer through the gas across each of the structures, determining two heat transfer parameters (q₁, q₂) indicative of the heat transfer through the gas across the two structures, and determining the gas-specific parameter (Hp; I_W; c_pρ) based on the heat transfer parameters (q₁, q₂). At least one of the heat transfer parameters (q₁, q₂) reflects a divergence from a thermal conduction regime in which a mean free path length (ℓ) in the gas is negligibly small compared to the sensor dimensions (d1, d2). In particular, the heat transfer parameters (q₁, q₂) can comprise a temperature jump length parameter (g) indicative of a temperature jump length of the gas.