Boost Controls for Aero‐Engines

THE power output from an engine is roughly proportional to the absolute pressure of the charge mixture in the induction system. If we take a normally aspirated engine, the maximum power output is obtained when the induction pressure is raised to atmospheric pressure by opening the throttle to wide open. The power output may be lowered by reducing the induction pressures by part closing the throttle. The power output could be increased by supplying the induction gases at a pressure higher than atmospheric. This can be done by attaching a supercharger to the engine which, drawing air at atmospheric pressure, will deliver it to the induction system at a pressure higher than atmospheric, and the greater the pressure of delivery, the greater will be the power output.