SIMULATION

A technique is proposed for reducing the number of repetitious solu tions required to carry out a conventional parametric study of a theoretical problem. The technique is potentially applicable to a particular class of problems which involve the numerical solution of differential equations. An applicability criterion is presented, along with a method for predicting the errors which may be expected in problems which do not satisfy the criterion exactly.

In this article an algorithm is developed to solve the equations for one-dimensional unsteady flow of compressible fluids in the presence of area change, wall friction, heat transfer, and entropy gradients. The algorithm is based on a rectangular mesh solution of the cor responding characteristics equations in the space-time plane. It is arranged in a generalized form to permit convenient application to a variety of engineering systems. A model of the gas exchange process occurring in a two-stroke internal combustion engine with intake and exhaust ducts is used to demonstrate application of the algorithm and to observe the accuracy and stability of solutions with varying mesh-step size.