Preliminary Study of Pressure Drop and Heat Transfer Through a Friction Stir Channel


Commercially available compact heat exchangers are currently fabricated in several steps by joining multiple tubes, or by independently fabricting and joining fluid channels. Friction stir channeling (FSC) is a simple and innovative technique of manufacturing heat exchangers in a single step in a monolithic workpiece. During friction stir welding (FSW), a defect referred to as 'wormhole', is created if the processing parameters (tool traverse speed, tool rotation speed, and tool plunge depth) are not correct. FSC is based on converting this defect formation during FSW into a manufacturing technique for heat exchanger applications. If used to produce a cooling system or heat exchanger, FSC can provide many benefits over standard industrial practices in terms of simplicity in manufacturing. Experiments have shown that a continuous hole in a single plate can be created by selecting the optimum process parameters. The channel is characterized by roughness features on the inside, which can be analyzed using optical microscopy techniques. In this paper, five such channels with different hydraulic diameters are tested for the pressure drop and heat transfer. The thermal behavior of a friction stirred channel is simulated using the commercial CFD code FLUENT. Pressure drop along the channel is studied for different surface roughness heights. Temperature difference of water between the inlet and the outlet of the channel is also measured for the channels.

Meeting Name

ASME International Mechanical Engineering Congress and Exposition (2007: Nov. 11-15, Seattle, WA)


Mechanical and Aerospace Engineering

Second Department

Materials Science and Engineering

Keywords and Phrases

Defect formation; Friction stir channeling (FSC); Optimum process parameters; Compact heat exchanger; Friction stir welding (FSW); Industrial practices; Innovative techniques; Manufacturing techniques; Microscopy technique; Processing parameters; Temperature differences; Cooling systems; Friction welding; Parameter estimation; Pressure drop; Surface defects; Computational fluid dynamics; Drops; Flow of fluids; Friction; Heat transfer; Joining; Manufacture; Surface roughness; Tribology; Channel flow; Heat exchangers

International Standard Book Number (ISBN)


Document Type

Article - Conference proceedings

Document Version


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© 2008 American Society of Mechanical Engineers (ASME), All rights reserved.

Publication Date

01 Nov 2008

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