Roughness effects on flow and heat transfer in a ribbed duct considering additive manufacturing

Edward Kilpatrick, Sung in Kim

Research output: Chapter in Book/Report/Conference proceedingConference contribution

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Abstract

With the advent of additive manufacturing (AM) and the technological improvements of AM, its potential utilization in gas turbine components manufacturing has been extensively explored nowadays. The AM will increase the turbine design space to develop advanced cooling schemes with improved cooling efficiency. However, the large surface roughness, particularly in small internal geometries, becomes one of key challenges. The effects of surface roughness, inherently caused by AM, on pressure loss and heat transfer are of interest. The thermo-fluidic behaviours in a ribbed duct and the effects of surface roughness on the heat transfer performance are numerically studied using a commercial CFD solver, ANSYS Fluent.
The computational treatments of surface roughness are explored against the experimental results of the additively manufactured channel flows. The appropriateness of the conventional empirical correlations of the equivalent sandgrain roughness height to the arithmetic mean roughness is evaluated in the AM channel flows. A new correlation which best fits the relationship between the arithmetic mean height and sand grain height is proposed to accurately implement the experimental data into simulations.
The accuracy and suitability of the numerical model is validated against the existing experimental results of a stationary duct with square ribs 45 degree angled to the main flow direction. Additional computations are done for the application of different surface roughness representing AM finishing. The influence of the increase in surface roughness are discussed and presented in terms of Nusselt number and skin friction coefficient. The detrimental effect of the surface roughness on the heat transfer performance in a ribbed duct flow is observed.
Original languageEnglish
Title of host publicationProceedings of GPPS Forum 18: 2018 Global Power and Propulsion Society's European Forum
PublisherGPPS
Number of pages8
Publication statusPublished - 10 Jan 2018
EventGlobal Power & Propulsion Forum 2018: 2018 Global Power and Propulsion Society's European Forum - ETH Zurich, Zurich, Switzerland
Duration: 10 Jan 201812 Jan 2018
https://www.gpps.global/gpps-forum-18.html

Conference

ConferenceGlobal Power & Propulsion Forum 2018
Abbreviated titleGPPF 2018
CountrySwitzerland
CityZurich
Period10/01/201812/01/2018
Internet address

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