0
Research Papers: Forced Convection

Proposed Modification to Whole Domain Function Specification Method to Improve Accuracy of Its Estimations

[+] Author and Article Information
Cha’o-Kuang Chen

Department of Mechanical Engineering,  National Cheng Kung University, Tainan 70101, Taiwan, R.O.C.ckchen@mail.ncku.edu.tw

Li-Wen Wu, Yue-Tzu Yang

Department of Mechanical Engineering,  National Cheng Kung University, Tainan 70101, Taiwan, R.O.C.

1

Corresponding author.

J. Heat Transfer 130(5), 051702 (Apr 10, 2008) (8 pages) doi:10.1115/1.2884184 History: Received August 10, 2006; Revised November 15, 2007; Published April 10, 2008

This paper investigates the inverse heat transfer problem of laminar forced convection within a circular pipe. The performances of two classical algorithms used in the whole domain function specification method (WDFSM) to obtain simultaneous estimates of the time-varying inlet temperature and outer-wall heat flux are compared. Additionally, this study proposes a modification to the linear assumption employed in the conventional WDFSM to improve its estimation performance. The WDFSM solution procedure is based on future temperature measurements at two different locations within the pipe flow. In the modified algorithm, the variations of the estimations at all time steps for various values of the future-time parameter are investigated, and if large variations in the slope of the function are detected at some time steps, the originally linear assumption for the variation of the unknowns is replaced with the assumption of a constant function at these time steps. Otherwise, the estimates at the other time steps are calculated using the linear assumption. The numerical results confirm that the proposed algorithm yields slightly more accurate estimates of the unknowns than the two classic algorithms.

FIGURES IN THIS ARTICLE
<>
Copyright © 2008 by American Society of Mechanical Engineers
Your Session has timed out. Please sign back in to continue.

References

Figures

Grahic Jump Location
Figure 1

System under consideration. Note that the velocity profile is fully developed and that the inlet temperature is uniform. (q(t) and f(t) denote the outer-wall heat flux function and the inlet temperature function, respectively.)

Grahic Jump Location
Figure 2

Time steps for use in modified algorithm obtained from intersection points of piecewise approximate slope lines

Grahic Jump Location
Figure 3

The dimensionless boundary conditions and simulated measured temperatures at downstream locations with measurement error of 3%

Grahic Jump Location
Figure 4

Estimated dimensionless inlet temperature distributions for measurement error of 3% obtained using different values of future-time parameter in (a) Algorithm 1 and (b) Algorithm 2

Grahic Jump Location
Figure 5

Estimated dimensionless outer-wall heat flux distributions for measurement error of 3% obtained using different values of future-time parameter in (a) Algorithm 1 and (b) Algorithm 2

Grahic Jump Location
Figure 6

Identification of time steps for use in modified algorithm

Grahic Jump Location
Figure 7

Optimum estimation results obtained from three algorithms for (a) inlet temperature and (b) outer-wall heat flux with measurement error of 3%

Grahic Jump Location
Figure 8

Variation of rms error with future-time parameter for three algorithms for (a) inlet temperature, ΔdΘ, and (b) outer-wall heat flux, ΔdQ, for measurement errors of 1% and 3%

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