Numerical simulation of oscillatory flow and heat transfer in the heat exchangers of thermoacoustic systems.

The design of appropriate heat exchangers is an essential requirement for the development of next generation of thermoacoustic systems. In this study, RANS method with SST k-ω turbulence model was applied to solve the time-dependent turbulent Navier-Stokes and energy equations for oscillating flow and heat transfer conditions in three individual but similar parallel plate heat exchangers, arranged in series and positioned in an oscillating helium gas environment. The numerical code is validated by comparing the low amplitude oscillating flow results to the analytical solutions found in the literature. The effects of pressure oscillation on the velocity and temperature distributions are discussed in detailed with respect to the channels’ entrance and exit edge shapes of the heat exchangers. Three types of edge shapes, blunt, cone and ogive, in this study influence the oscillating flow behaviour and heat transfer condition differently at the entrance and exit of the heat exchanger channels.