Thermodynamics and Energy

2502 Submissions

[2] viXra:2502.0149 [pdf] submitted on 2025-02-21 22:13:15

Stirling Alpha Engine with Circulation

Authors: Josef Bukac
Comments: 3 Pages. (Note by viXra Admin: An abstract in the article is required)

Stirling engine of type alpha is the field to which this paper belongs. Such engines are used for micro-co-generation of electric power. So far, we were able to find references to those sources of heat for which the temperature is easily kept constant, such as natural gas or pellets. For more independent source of heat we want to consider firewood burnt in a wood stove. We are presenting an idea of circulation of the working gas to increase the temperature difference enabling the engine to run under varying conditions. The circulation makes sense if there is a way of cooling the working gas.
Category: Thermodynamics and Energy

[1] viXra:2502.0059 [pdf] submitted on 2025-02-09 10:45:28

Energy Minimization in Fluid Flow Through Tubes and Networks of Various Geometries

Authors: Taha Sochi
Comments: 21 Pages.

In this paper we continue our previous investigation about energy minimization in the flow of fluids through tubes and networks of interconnected tubes of various geometries. We will show that the principle of energy minimization holds independent of the geometry of the tubes and networks of such interconnected tubes and independent of the type of fluid in such geometries where in this regard we consider generalized Newtonian fluids. We consider in this investigation the flow of Newtonian fluids through tubes and networks of interconnected tubes of elliptical, rectangular, equilateral triangular and concentric circular annular cross sectional geometries. We also consider a combination of geometric factor with a fluid type factor by showing that the principle of energy minimization holds in the flow of some non-Newtonian fluids (namely power law, Ellis and Ree-Eyring fluids) through tubes and networks of interconnected tubes of elliptical cross sections. The relevance of this study extends beyond tubes and networks of fluid flow to include for instance porous media and electrical networks.
Category: Thermodynamics and Energy