Aviation Dictionary
توان مفید ، توان حقیقی موتور که باعث تولید نیروی کششی می شود ، حداکثر توان موتور که بتواند بر نیروی ترمزِ prony غلبه کند
The horsepower actually delivered to the output shaft of a rotating machine. Brake horsepower gets its name from the fact that this power was originally measured with a prony brake. Today, brake horsepower is measured with a dynamometer. BHP is actually the usable horsepower.