SUPERCHARGING PRESSURE CALCULATING METHOD AND INTAKE SYSTEM DESIGNING METHOD IN ENGINE EQUIPPED WITH MECHANICAL SUPERCHARGER

摘要

PURPOSE:To improve supercharging pressure computation accuracy by seeking the condition that makes intake flow and discharge flow computation values mutually equal and also these values and delivery flow given by supercharging characteristic equal under the terms off identical pressure ratio and engine speed and finding the supercharging pressure under this condition. CONSTITUTION:An intake system, excluding a mechanical supercharger 1, is made into models as a combination of sub-models of a pipe model, a container model, etc., and quantity of state of pressure, flow, temperature, etc., of respective sections regarding the intake mode models are computing-processed. The supercharger 1 is made into a model of two containers of intake and delivery sides and intake and delivery flows are computed in accordance with relational expression of the quantity of state at the joint parts of respective containers and intake pipes per model. A condition under which flow computed values and the delivery flows given by supercharger characteristic data indicating the characteristic of the supercharger itself becomes equal under the terms of identical pressure ratio and engine speed is seeked and the supercharging pressure and other quantity of state are found by repeating such process by each certain assuming time until the quantity of state converges.