Analysis of unsteady heat transfer of internal combustion engines’ exhaust valves

Abstract

This study is concerned with the analyses of heat transfer through an exhaust valve considering the real unsteady effects during the cycle of an internal combustion engine and to identify the factors and parameters affecting the heat transfer. The valve is segmented into several zones to facilitate incorporating the boundary conditions and evaluating the heat transfer coefficient and the adiabatic wall temperature based on the finite element method. The unsteady simulations were carried out using ANSYS-APDL for the proposed thermal model. The effect of lubricating oil and the contact resistance between guide and engine block and the thermal contact between exhaust valve and seat are included, as well as the differential displacement of both the guide and engine block walls due to high working temperature. The averaged values of heat transfer coefficient and adiabatic wall temperature used in the boundary conditions are shown to underestimate the temperature maps. The cyclic boundary conditions required more run time to reach the steady state and allowed better monitoring of the thermal process. The thermal contact resistance has the main contribution in the zone of valve-seat, whereas the resistance of oil film between the guide and stem valve is shown to affect mainly heat transfer coefficient. The obtained maps of temperature reveal the locations of maximum temperatures in the exhaust valve.

Keywords

Exhaust valve internal combustion engine unsteady heat transfer heat transfer coefficient temperature maps

Get full access to this article

View all access options for this article.

References

Gibson

Wright Baker

. Exhaust-valve and cylinder-head temperatures in high-speed petrol engines. Proc Instn Mech Engrs 1923; 105: 1045–1119.

Zipkin

Sanders

. Correlation of exhaust-valve temperatures with engine operating conditions and valve design in an air-cooled cylinder. NASA report no. 813, 1945, https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19930091891.pdf

Pandey

Mandloi

. Effects of high temperature on the microstructure of automotive engine valves. Int J Eng Res Appl 2014; 4(3): 122–126.

Annand

WJD

. Heat transfer in the cylinders of reciprocating internal combustion engines. Proc Instn Mech Engrs 1963; 177(36): 973–990.

Stotter

Woolley

. Exhaust valve temperature – a theoretical and experimental investigation. SAE Trans 1966; 74: 89.

Woschni

. Electronic calculation of the time curve of pressure, temperature and mass flow rate in the cylinder of a diesel engine (Computers in internal combustion engine design). Proc Instn Mech Engrs 1967; 182(12): 71–78.

Annand

WJD

Lanary

. Heat transfer measurements on a simple model representing a poppet exhaust valve in an outflowing stream. J Mech Eng Sci 1970; 12(3): 223–229.

Cerdoun

Carcasci

Ghenaiet

. An approach for the thermal analysis of internal combustion engines’ exhaust valves. Appl Therm Eng 2016; 102: 1095–1108.

Mavropoulos

. Experimental study of the interactions between long and short-term unsteady heat transfer responses on the in-cylinder and exhaust manifold diesel engine surfaces. Appl Energ 2011; 88(3): 867–881.

10.

Anderson

Moffat

. The adiabatic heat transfer coefficient and the superposition kernel function: part II modeling flat pack data as a function of turbulence. J Electron Packaging 1992; 114: 22–28.

11.

Heywood

. Internal combustion engine fundamentals (International editions). New York: McGraw-Hill, 1988.

12.

Han

Chung

Kwon

Lee

. Empirical formula for instantaneous heat transfer coefficient in spark ignition engines. SAE paper 972995, 1997.

13.

Hohenberg

. Advanced approaches for heat transfer calculation. SAE paper 790825, 1979.

14.

Annand

WJD

. Instantaneous heat transfer rates to the cylinder head surface of small compression-ignition engine. Proc. Instn Mech. Engrs 1970–1971, 185: 976–987.

15.

Woschni

. A universally applicable equation for the instantaneous heat transfer coefficient in the internal combustion engine. SAE paper 670931, 1967.

16.

Watson

Janota

. Turbocharging the internal combustion engine. London: Macmillan Education, 1982.

17.

Wallace

. High-output medium-speed diesel engine air and exhaust system flow losses. Proc Instn Mech Engrs 1967; 182: 134–158.

18.

Kastner

Williams

White

. Poppet inlet valve characteristics and their influence on the induction process. Proc Instn Mech Engrs 1963; 178(1): 951–978.

19.

Mikic

. Thermal contact conductance theoretical considerations. Int J Heat Mass Tran 1974; 17(2): 205–214.

20.

Cooper

Mikic

Yovanovich

. Thermal contact conductance. Int J Heat Mass Tran 1969; 12: 1517–1520.

21.

Sridhar

Yovanovich

. Elastoplastic contact conductance model for isotropic conforming rough surfaces and comparison with experiments. J Heat Trans: T ASME 1996; 118(1): 3–9.

22.

Carcasci

Facchini

. A numerical procedure to design internal cooling of gas turbine stator blades. Rev Gén Therm 1996; 35(412): 257–268.

23.

Churchill

Bernstein

. A correlating equation for forced convection from gases and liquids to a circular cylinder in crossflow. J Heat Trans: T ASME 1977; 99: 300–306.

24.

Engh

Chiang

. Correlation of convective heat transfer for steady intake flow through a poppet valve. SEA paper 700501, 1970.

25.

Madhusudana

. Thermal conductance of cylindrical joints. Int J Heat Mass Tran 1999; 42: 1273–1287.

26.

Ugural

Fenster

. Advanced strength and applied elasticity. New York: Elsevier, 1976, pp.255–256.

27.

Roache

. Perspective: a method for uniform reporting of grid refinement studies. J Fluid Eng: T ASME 1994; 116(3): 405–413.

28.

Coleman

Glenn Steele

. Experimentation and uncertainty analysis for engineers. 2nd ed. New York: John Wiley & Sons, Inc., 1999.