Testing the cooling system of the helicopter internal combustion engine in hot climates

The article discusses the need to solve the problem of increasing the temperature limits of the operation of the cooling system of the internal combustion engine (ICE) of the helicopter. This issue arose from the fact that during the operation of the helicopter on the territory of African countries with a hot climate, the engine overheated. The use of helicopters in these conditions was due to the demand in the aviation market. To solve the problem, new elements of the cooling system were selected, i.e. radiator and two types of fans. The research was aimed at increasing the heat transfer from the radiators of the cooling system by increasing the size of the radiator and increasing the air flow rate through the radiator. 3D modeling, design of a new cooling system (CO), and then design of CO in two versions with TEMIC and SPAL fans were done. First, ground and flight tests for two prototypes in a temperate climate were done, as a result of which a prototype with the best performance parameters was determined. During the tests the equipment and measuring instruments were used: voltmeter, ammeter, voltmeter; shunt; motor tester with the ability to transfer data via Bluetooth; smartphone with OpenDiag software installed, which is included and connected to the motor tester via Bluetooth, helicopter objective control system, flight data registration system, equipment and devices normally installed on the helicopter. For flight tests in hot climates, a new cooling system with a SPAL fan was used, these tests lasted three days. This article describes the final stage of a series of tests for the effectiveness of the cooling system of a helicopter and an analysis of the results obtained with confirmation of the final achievement of the set goals, i.e. raising the upper temperature limit of the outside air for the safe operation of the helicopter.