Numerical and experimental modeling for thermal developing pipe flow with microwave heating

The work here presented is concerned with the analysis of forced convection of Newtonian liquids flowing in a circular duct under microwave heating. Spatial temperature field in the illuminated cavity was numerically obtained by solving coupled energy and Maxwell’s equations since it was assumed to be dependent on the dielectric properties of the fluid flowing in the duct. Attained temperature levels justified no phase changes and no gas phases. Temperature contour is detected by an outer infrared camera looking inside the microwave chamber in correspondence of the applicator-pipe. The proposed procedure is intended to realize relatively high spatial resolution temperature readings while microwave heating takes place. In facts, temperatures are usually measured in few points which can’t enable a proper temperature profile reconstruction, the latter being strongly uneven along the pipe due to electromagnetic field distribution. Numerical results are compared with the corresponding experimental ones for different temperature levels, showing a good agreement.