The Evolution of Hush House Design for High-Thrust Jet Engines

As jet engine thrust has improved over the past few decades, the noise produced during ground testing has become a serious problem for technicians, local communities, and the environment. Noise pollution, especially when people are exposed to high-pressure noise levels for long periods of time, can cause physical and mental health problems. Also, if noise is not permitted to escape during testing of jet engines, hot air flow can become trapped inside the hush house, overheating and damaging or even exploding the engine.

Early hush houses consisted of simple acoustic enclosures. It could reduce direct noise transmission but could not satisfy the increasing thrust requirements of increasingly advanced modern jet engines, especially those flights with afterburners used for combat or supersonic flight. By modeling techniques, the hush house configuration must be calculated, along with an optimized system of airflow and the use of advanced acoustic control materials to solve these problems.

In order to ensure sufficient replaceable airflow, consistent temperature, and humidity in the hush house during the jet engine test, the cold air intake and hot air exhaust chambers should be simulated according to the flow, speed, and temperature of the hot and cold fluids during the jet engine operation. As for sound-absorbing materials, sound-absorbing panels should have a high heat dissipation, sound absorption, and fluid permeability to ensure the safety and accuracy of testing. The application of new materials and active noise reduction technology in hush houses can be improved by modular construction technology.

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