While the porous ice protection panels deliver fluid to the required surfaces, the internal system is equally important for achieving the protection. Therefore, design of the internal system components is a key element in ensuring correct operation of the system. Fluid is divided and volumetrically controlled to the external protection devices with proportioning units. The capillary tubes are calibrated (sized) to permit the proper flow rate through each outlet, appropriate to the fluid feed requirements of the panel or feed nozzle attached to the outlet line.
CAV Ice Protection developed software is used to perform the flow analysis of the system. The entire designed system is defined by an input file which includes, but is not limited to, all components (tees, elbows, solenoid valves, etc.) and tubing sizes and lengths. The desired flow rate for each panel is also input along with a pump curve for fluid delivery versus pressure. The system is then evaluated at the design temperature to appropriately size the proportioning unit capillary tubes. The software is further used to determine the pressure and flow rate characteristics of the system over the entire icing envelope temperature range.