FLUID FLOW AND HEAT TRANSFER SIMULATIONS OF THE COOLING-WATER CHANNEL IN A TERA-HERTZ RADIATION DETECTOR

Detailed numerical simulations have been carried out to find the velocity and temperature fields of a rectangular channel with large aspect-ratio. The channel under analysis is aimed to cool a thermo-chromic liquid crystal material (TLC) that is able to capture laser irradiation in the terahertz range. The overall objective of the cooling system is to maintain a nearly-homogeneous temperature of the TLC layer that is not exposed to the direct laser irradiation. The fluid flow and heat transfer simulations are carried out on the basis of three-dimensional versions of the Navier-Stokes equations, along with the energy equation, for an incompressible flow, to determine values of velocity, pressure and temperature inside the channel under different operating conditions. These values are then used to find, from a specific set, the value of the channel height that allows for the most uniform temperature distribution within the expected operating conditions. Results from this analysis indicate that, for all the inlet velocities considered, there is a common value of the channel height, that represents the optimum.