An example of the "Energy Balance" of the engine under test

Energy into the engine : Fuel 70kW, Energy out of the engine : Power 23kW, Exhaust 21kW, Engine cooling fluid 21kW, Convection/radiation 5kW. It will be noted that the total power through the test cell is greater than the power output of the engine under test. A simple rule of thumb is one-third share of each parameter for example: Power Absorbed, Exhaust Gas and Cooling energy dissipated. There are simplistic illustrations, but they clearly demonstrate some of the many factors that love to be taken into account when designing and planning a test cell.