A CFD analysis of the pressure drop through misaligned Stirling engine regenerators

Abstract

Experiments were conducted to discover the average misalignment in wire mesh regenerators, and it was found that regardless of the intended stacking arrangement, the average misalignment was 44% to 49%. A 3-dimensional CFD model was validated against previous empirical results, and used to determine the effect of wire mesh misalignment on the pressure drop for ow through a regenerator. A friction factor correlation equation was developed and it was found that a perfectly aligned regenerator could result in a 38% to 45% decrease in pressure losses. The model was also used to determine the influence of axial spacing on the pressure drop, and it was found to be dependent on the misalignment, with pressure loss reductions only being realized in highly misaligned cases. As a result of this thesis, Stirling designers can confidently disregard alignment and spacing when assembling wire mesh regenerators, and can more accurately calculate the pressure losses.