Heat transfer in wide-aperture absorbing loads of liquid microwave calorim

Using the CST Microwave Studio program, thermal processes were simulated in wide-aperture disk-shaped absorbing loads of calorimeters with a working fluid based on ethyl alcohol while absorbing the energy of high-power microwave pulses. The loads with flat and ribbed input windows at carrier frequencies 3 and 10 GHz were investigated. We analyzed the features and optimal conditions for using the CST Microwave Studio package in relation to the tasks being solved. For flat input windows, simulation results are compared with analytical estimates based on the problem of cooling a half-space filled with a homogeneous medium having a temperature jump at the initial moment of time. Time dependences of heat leakage from working fluid into the input windows were obtained during time interval of the high-power microwave pulses energy measurement with the calorimeter. The underestimation of the measured energy relative to the microwave energy released in the working fluid was calculated.