Technical Paper
A One-Dimensional Model for Heat Transfer in Engine Exhaust Systems
2005-04-11
2005-01-0696
This paper presents a one-dimensional model for heat transfer in exhaust systems. Convective heat transfer in pipe flows under steady-state and transient conditions is studied. Analytical solution of the governing equation for steady-state condition is obtained. Effects of turbulent, laminar and transition flow regimes on heat transfer are allowed for. Influences of various parameters, i.e. inlet mass flow rate & temperature, wall temperature, pipe length and pipe diameter, on heat transfer are assessed quantitatively. Efforts are made to explain the physics of heat transfer process from basic principles. It is proven mathematically that in turbulent flow regime, the pipe outlet temperature increases with increasing pipe diameter and mass flow. For transient condition, the governing equations are derived, and a warm-up process is simulated. Effects of inlet condition, pipe geometry, external heat transfer and wall thickness on outlet temperature are discussed.