In designing a gas turbine, we are often confronted with cases, where the blade length is given. Meanwhile in usual design method, the blade length is not known, until entire calculation is over. Coincididing this calculated length with given one requires tedious repitions and time. The new method is explained with an example for both the compressor and power turbine. This uses Mc2, the Mach mumber of exit velocity c2 as its parameter. By adopting this method, the number of repition times is reduced conciderably, and the repitition becomes much simpler, thus saving lots of time and labor.
