Application of Random-Choice Method to the Calculation of Unsteady Flow in Pipes

Unsteady flows in exhaust and intake pipes of reciprocating engines have been solved graphically and numerically by the method of characteristics. In the present paper the Random-Choice Method(RCM) has been used to solve similar unsteady flow problems. In particular, the flow pattern produced by a rotary valve in a pipe of constant area has been calculated, and the results compared with experiment. The effects of wall friction, heat transfer at the wall and heat conduction through the wall have been taken into account in the calculation. The good agreement obtained shows that the RCM may also be used to solve unsteady flow problems associated with the air exchange process in reciprocating engines.