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Full-Text Articles in Engineering

Technical Note: Friction Factor Diagrams For Pipe Flow, Jim Mcgovern Oct 2011

Technical Note: Friction Factor Diagrams For Pipe Flow, Jim Mcgovern

Articles

This technical note describes diagrams of friction factor for pipe flow that have been prepared using, mainly, the equations that Lewis Moody used to prepare his famous diagram in 1944. The preparation of the new diagrams was prompted by the need for vector graphics versions that could be used for teaching purposes and that could be distributed freely to students and others under a Creative Commons Attribution-Share-Alike license. Using a structure very similar to that of Moody's diagram, variants with the Darcy friction factor and the Fanning friction factor have been prepared. In addition, variants have been prepared that include …


Rational Efficiency Of A Heat Exchanger, Jim Mcgovern, Brian P. Smyth Sep 2011

Rational Efficiency Of A Heat Exchanger, Jim Mcgovern, Brian P. Smyth

Articles

The authors propose a new and unique definition for the rational efficiency of a heat exchanger. This new rational efficiency is defined in terms of its sub-rational efficiencies: a heat transfer rational efficiency and a friction rational efficiency for each of the fluid systems comprising the heat exchanger. The heat transfer rational efficiency is based on the definition of a mean temperature for the heat source and a mean temperature for the heat sink and reflects the exergy supplied and the exergy received, due to heat transfer only. The friction rational efficiency for each fluid system of the heat exchanger …


Some Experiences, Thoughts, Ideas And Open Questions Relating To Applied Thermodynamics, Jim Mcgovern Apr 2011

Some Experiences, Thoughts, Ideas And Open Questions Relating To Applied Thermodynamics, Jim Mcgovern

Articles

In this paper I present some of my thoughts and experiences relating to 'applied thermodynamics' over my career so far. I explain my interest in thermodynamics, describe some topics I have worked on, point out some questions that appear still to be open and outline some ideas for work that could be done. I describe how I was inspired to pursue the area of applied thermodynamics, with reference to a glass, opposed-piston internal combustion engine. I put my heat pump research in the late 1970s briefly into today's context. Some of my research has been in relation to compressors, which …