0
Research Papers: Forced Convection

Instantaneous Heat Flux Simulation of a Motored Reciprocating Engine: Unsteady Thermal Boundary Layer With Variable Turbulent Thermal Conductivity

[+] Author and Article Information
Abdalla Agrira

e-mail: abdalla.agrira@gmail.com

David R. Buttsworth

e-mail: david.buttsworth@usq.edu.au

Mior A. Said

Faculty of Engineering and Surveying,
University of Southern Queensland,
West Street, Toowoomba,
Queensland 4350, Australia

1Corresponding author.

Contributed by the Heat Transfer Division of ASME for publication in the JOURNAL OF HEAT TRANSFER. Manuscript received May 11, 2012; final manuscript received September 27, 2013; published online November 28, 2013. Assoc. Editor: Wei Tong.

J. Heat Transfer 136(3), 031703 (Nov 28, 2013) (9 pages) Paper No: HT-12-1216; doi: 10.1115/1.4025639 History: Received May 11, 2012; Revised September 27, 2013

Due to the inherently unsteady environment of reciprocating engines, unsteady thermal boundary layer modeling may improve the reliability of simulations of internal combustion engine heat transfer. Simulation of the unsteady thermal boundary layer was achieved in the present work based on an effective variable thermal conductivity from different turbulent Prandtl number and turbulent viscosity models. Experiments were also performed on a motored, single-cylinder spark-ignition engine. The unsteady energy equation approach furnishes a significant improvement in the simulation of the heat flux data relative to results from a representative instantaneous heat transfer correlation. The heat flux simulated using the unsteady model with one particular turbulent Prandtl number model agreed with measured heat flux in the wide open and fully closed throttle cases, with an error in peak values of about 6% and 35%, respectively.

FIGURES IN THIS ARTICLE
<>
Copyright © 2014 by ASME
Your Session has timed out. Please sign back in to continue.

References

Figures

Grahic Jump Location
Fig. 1

Location of thermocouple gauges and pressure sensor in the head of the engine

Grahic Jump Location
Fig. 2

Variation of turbulent thermal conductivity as a function of distance from the wall for the WOT case

Grahic Jump Location
Fig. 3

Effect of different thermal boundary layer thicknesses on peak heat flux for the WOT case

Grahic Jump Location
Fig. 4

Heat flux sensitivity to node spacing for the WOT case

Grahic Jump Location
Fig. 5

Averaged in-cylinder measured pressure and the simulated pressure for WOT case. Simulation used Eichelberg's formula with αs = 4.035.

Grahic Jump Location
Fig. 6

Heat flux from different measuring locations for WOT case

Grahic Jump Location
Fig. 7

Measured and simulated heat flux using Eichelberg's model with a scaling factor of 4.035 for the WOT case. Experimental data from the averaged heat flux for the three probes.

Grahic Jump Location
Fig. 8

Measured and simulated heat flux using the unsteady model for WOT case with constant turbulent Prandtl number values in the thermal conductivity model. Experimental data from the averaged heat flux for the three probes.

Grahic Jump Location
Fig. 9

Measured and simulated heat flux using the unsteady model for WOT case with variable turbulent Prandtl number in the thermal conductivity model. Experimental data from the averaged heat flux for the three probes.

Grahic Jump Location
Fig. 12

Measured and simulated heat flux using Eichelberg's model with a scaling factor of 0.208 for the FCT case. Experimental data from the averaged heat flux for the three probes.

Grahic Jump Location
Fig. 13

Measured and simulated heat flux using the unsteady model for FCT case with constant turbulent Prandtl number values in the thermal conductivity model. Experimental data from the averaged heat flux for the three probes.

Grahic Jump Location
Fig. 14

Measured and simulated heat flux using the unsteady model for FCT case with variable turbulent Prandtl values in the thermal conductivity model. Experimental data from the averaged heat flux for the three probes.

Grahic Jump Location
Fig. 10

In-cylinder measured and simulated pressure for FCT case. Simulation used Eichelberg's formula with αs = 0.208.

Grahic Jump Location
Fig. 11

Heat flux from different measuring locations for the FCT case

Tables

Errata

Discussions

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In