![]() Three approaches can be proceeded to alleviate or even eliminate this defect: (1) redesign the engine cowling to improve ventilation during the hover operations (2) fabricate the engine cowling with a higher thermal resistant material or (3) replace the current epoxy seal coat with ceramic coating materials that are efficient after extended exposure to heat.Īfter weighing the three options, researchers from Mississippi State University and Airbus Helicopters decided that the third approach was the most time- and cost-effective solution and could be easily implemented into a current production line once its effectiveness was verified. In this state, the internal cowling temperature is estimated to be between 177 and 220☌, which exceeds the maximum recommended service temperature of the coating material currently being used and causes the failure on the inner skin of the engine cowlings. However, during hover operations a steady state temperature of about 343☌ will be reached. ![]() ![]() Thermal imaging data obtained from a FLIR high-performance camera shows that the expected turbine output temperature is approximately 285☌ when the helicopter is in forward flight. With insufficient airflow to cool the area off around the engine cowling, the heat buildup can contribute to the premature degradation of the cowling inner skin and can cause burning of the reinforcement material, delamination of the skin plies, core degradation, blistering, and resin crystallization. This heat buildup contributes to the premature degradation of the cowling inner skin and can cause burning of the reinforcement material, delamination of the skin plies, core degradation, blistering, and resin crystallization. During extended hover operations, excessive heat radiated from the engine accumulates in the engine compartment, which is encapsulated by the engine cowlings, without sufficient airflow to cool the area off. When a helicopter is hovering, there is little airflow passing through the engine cowling and hot stagnant air will gather in the engine compartment. Broge Thermal imaging data obtained from a FLIR high-performance camera show that the expected turbine output temperature is approximately 285☌ when the helicopter is in forward flight.
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