1. VOLUMETRIC HEAT TRANSFER VIA CONSTRUCTAL THEORY, AND ITS
APPLICATIONS IN PERMAFROST AND HYDROGEN ENERGY STORAGE
By
Vamsi Krishna Kukkapalli
“For a finite-size flow system to persist in time (to live) it must evolve in such a way that it
provides greater and greater access to its currents”……(Constructal law by Dr. Adrian Bejan)
Evidense of Constructal law in nature
(Tree & Lightning bolt structures)
Temperature distribution of 6-fin Metal hydide reactor
Existing parallel configuration Tree shape inspired configurations of thermosyphon evaporator with incresing bifurcation levels in constuctal theory
Department of Mechanical Engineering, MS Project Defense
Duckering 531, April 14th
3:00PM
Constructal theory is widely used as a powerful tool in of designing
engineering systems (flow configurations, patterns, geometry). This theory
is observed in nature and its principles are applicable to general
engineering. Constructal theory encompasses a wide range of space in the
“design”, drawing from each and every field from engineering to biology.
The universal design of nature and the constructal law unify all animate
schemata such as human blood circulatory systems, and inanimate systems,
such as urban traffic and river basins. The current research focuses on two
systems. (i) The first is stabilization of roadway embankments in the
permafrost regions with design modifications in existing thermosyphon
evaporators with tree structure designs, and defining the optimal spacing
between two neighboring thermosyphons based on thermal cooling
phenomena. The mathematical simulation revealed that there exists an
optimal spacing between two neighboring thermosyphons, and the tree
structures perform better than the existing configuration in terms of thermal
cooling. (ii) The second part of the research is to find efficient designs for
metal hydride reactors for hydrogen absorption process, as well as
optimizing heat transfer which is generated during exothermic hydriding
reaction. The main objective of this investigation is to minimize the time
required for the absorption process and to reduce the hotspot temperature
by determining the number and shape of rectangular fins, while the total
volume of fins used is kept constant. By application of the constructal
theory, the optimal aspect ratio of a fin is derived. The simulation revealed
that there exists an optimum aspect ratio of rectangular fins for accelerating
heat rejection and lowering the hotspot temperature in a cylindrical metal
hydride reactor.