Keywords: exergy losses, non-inverted skew upwind scheme, NISUS, finite volume method, entropy production, exergy destruction, convective exergy, microfluidics, irreversibilities, microchannels, pressure losses, fluid friction, power input, energy efficiency
Finite volume computations of convective exergy losses in microfluidic devices
Exergy losses affect the net power required to transport fluid through microfludic devices. Unlike pressure losses or friction factors, modelling of exergy losses can encompass all types of irreversibilities within a microsystem, including thermofluid, chemical and electromagnetic irreversibilities. In this paper, a finite volume method with a SIMPLEC formulation is developed to predict exergy losses in microchannels. The continuum Navier?Stokes equations are solved numerically with a slip-flow boundary condition. The implications of the two coefficients on exergy destruction, involved in the first-order boundary model, are investigated. By reducing exergy destruction within the microchannel, pressure losses and fluid friction can be minimised to reduce power input and improve overall energy efficiency.