| Popis: |
Increase of the capacity of heavy duty diesel engines is of great interest in the way of power enhancement in many engine applications. Turbocharger is one of the most important ways used to increase the engine specific power. The present study aimed to develop an analytical model to simulate the performance and combustion characteristics of a direct injection diesel engine. This model depends on the basic conservation equations of continuity, momentum and energy as well as equation of state, these equations are solved together numerically by using two steps Lax-Wendroff scheme. To address this, a comprehensive computer “FORTRAN” code was developed and applied to study the performance and combustion characteristics of a six-cylinder, four stroke, direct injection, heavy duty diesel engine as a base engine and when its power upgraded by 15% using a turbocharger. This code is open source, preprocessor is user-friendly and very easy in work and will used at any time. The computed results are compared with the results obtained by applying the engine simulation DIESEL-RK software. But the DIESEL-RK solver may be run under the control of an external code. In that case the interface of the program includes input & output text files. Templates of these files are generated automatically. The developed model provides reasonable estimates and the experimental validation of the model show that an appropriate agreement between mathematical model, DIESEL-RK software, and the real measurements, in addition the capability of the model to predict satisfactorily the performance, and combustion characteristics of the direct injection diesel engine. Simulation study was also performed to compare the turbocharged engine with the naturally aspirated direct injection diesel engine. This study examined the engines for operating parameters like brake power and brake specific fuel consumption over the entire speed range and revealed that turbocharging offers higher brake power and lower brake specific fuel consumption values for most of the operating range. The results indicated that turbocharging offers marginally higher brake thermal efficiency and enhancing the engine performance.Copyright © 2015 by ASME |
