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Our customer is India’s largest aerospace organization engaged with design, fabrication and assembly of military aircrafts and jet engines. During aircraft high AOA steady flight, rapid maneuvering and departures (especially during combat situation) the efficiency and performance of its propulsion system are abruptly affected due to uneven flow passing the engine inlet. This may result into unexpected engine fouling. Measuring this inlet flow unevenness by flight and wind tunnel tests is a time consuming and costly process.

Zeus Numerix used CFD generated flow field data at inlet plane and an in-house distortion-descriptor module to estimate flow distortion to engine inlet. The flow distortion was measured, analyzed and studied for unsteady and different steady maneuvering conditions. Illustration 1 shows a xi-distortion descriptor pattern on inlet sampling plane during a flight with high side slip angle. The pattern describes a high level of flow distortion to left intake, which may cause engine-shutdown.

Customer was provided with inlet plane distortion data for both original aircraft configuration and on a configuration, where a large supersonic missile was integrated in its belly. The study helped our customer to obtain approval from certification agency towards missile integration.