Version 1
: Received: 14 August 2024 / Approved: 14 August 2024 / Online: 14 August 2024 (16:58:10 CEST)
How to cite:
Hartmann, C.; von Wolfersdorf, J. Determination of Local Heat Transfer Coefficients and Friction Factors at Variable Temperature and Velocity Boundary Conditions for Complex Flows. Preprints2024, 2024081092. https://doi.org/10.20944/preprints202408.1092.v1
Hartmann, C.; von Wolfersdorf, J. Determination of Local Heat Transfer Coefficients and Friction Factors at Variable Temperature and Velocity Boundary Conditions for Complex Flows. Preprints 2024, 2024081092. https://doi.org/10.20944/preprints202408.1092.v1
Hartmann, C.; von Wolfersdorf, J. Determination of Local Heat Transfer Coefficients and Friction Factors at Variable Temperature and Velocity Boundary Conditions for Complex Flows. Preprints2024, 2024081092. https://doi.org/10.20944/preprints202408.1092.v1
APA Style
Hartmann, C., & von Wolfersdorf, J. (2024). Determination of Local Heat Transfer Coefficients and Friction Factors at Variable Temperature and Velocity Boundary Conditions for Complex Flows. Preprints. https://doi.org/10.20944/preprints202408.1092.v1
Chicago/Turabian Style
Hartmann, C. and Jens von Wolfersdorf. 2024 "Determination of Local Heat Transfer Coefficients and Friction Factors at Variable Temperature and Velocity Boundary Conditions for Complex Flows" Preprints. https://doi.org/10.20944/preprints202408.1092.v1
Abstract
Transient conjugate heat transfer measurements under varying temperature and velocity inlet boundary conditions at incompressible flow conditions were performed for flat plate and ribbed channel geometries. Therefrom local adiabatic wall temperatures and heat transfer coefficients are determined. Those data are analyzed using typical heat transfer correlations, e.g. Nu=CRe^mPr^n determining the local distribution of C and m. It is shown that they are closely linked. A relationship lnC=A−mB is observed with A and B as modeling parameters. They could be related to parameters in log law or power law representations for turbulent boundary layer flows. The parameter m is shown to have a close link to local pressure gradients and therewith near wall streamlines as well as friction factor distributions. A normalization of the C parameter allows to derive a Reynolds analogy factor and therefrom local wall shear stresses.
Copyright:
This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
