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Showing posts from April, 2025

Engineering Design of a Stirling Engine Integrating High-Temperature Combustion and Low-Temperature Cryogenic Sources

Engineering Design of a Stirling Engine Integrating High-Temperature Combustion and Low-Temperature Cryogenic Sources ABSTRACT While Stirling engine analysis using the ideal adiabatic model improves upon the isothermal model by accounting for heat exchange between hot and cold spaces it comes at the cost of complexity requiring the designer to solve for 16 variables and 22 differential equations.  Higher order analysis increases the complexity further by using CFD to analyse the engine. None of these methods answer the basic questions about engine design.  In this technical report we develop a set of equations that can help design a Stirling engine from scratch by reverse engineering from the power input and calculating plate area,stroke length,piston velocity and frequency of the engine along with the temperature at the hot end. We use the results to calculate the working volume of the engine and the pressure and temperature at the hot side to drive the output.  INTRODUC...

A Practical Design Method for Stirling Engine Regenerators Using First Principles

A Practical Design Method for Stirling Engine Regenerators Using First Principles ABSTRACT: Regenerators are critical components in Stirling engines that improve its efficiency by recycling heat between hot and cold transitions of the working gas. Although simple conceptually designing of Stirling engine regenerators is quite complex as it's not clear tuning which parameter produces what effect. Furthermore designing a regenerator may involve solving complex navier stokes equations using CFD tools. In this paper we focus on macro properties of the regenerator and present a unique solution that can be used to predict it's behaviour completely bypassing navier stokes equations and complexities that arise from it. Further we outline a simple method to build a foil type regenerator that is both highly efficient and minimises the pressure drop of the working gas.  Regenerators are probably the most important component in a Stirling engine. They act like a thermal sponge and absorb e...

UNSW: Driving Innovation Beyond the Rankings

 Had productive meetings today with representatives from University of New South Wales ,Australia.  As competition for talented students & faculty intensifies it has become important for educational  institutions to differentiate themselves. UNSW could do a lot better than its 19th rank on the global stage would suggest.  I was pleasantly surprised to learn that UNSW is focussing on academic research to create value & enhance it's well established reputation globally.  As one of Australia's premier institutions UNSW could have an important role to play in shaping Australia's scientific and technological direction. Breakthroughs are needed by Australia to kickstart it's Hydrogen economy. Research into generators,storage tanks and compressors for hydrogen will lead to rewards in the long run.  As energy storage techniques diversify UNSW could contribute in thermal energy storage systems -- sand batteries and liquified air being the most promising ones...

Nanotechnology or manufacturing ? Which one would I suggest and why?

You know one of the biggest problems in nanotechnology is actually manufacturing of nanomaterials.It turns out that breaking materials (chemically, mechanically or electrically) is not so easy. Neither is doing the opposite i.e bottom up synthesis.Making structural nanomaterials is prohibitively expensive. That is why no one is doing it.  I think integrated circuits are probably the biggest success story of nanotechnology. Everywhere else it is still very much a research topic. From the POV of getting a job manufacturing looks more appealing to me. I'm not familiar with the course topics but even in manufacturing you may need to specialise in some material system. Glass,steel,polymers , automation etc.  I think instead of choosing between academia or industry, balance it out. Understand the fundamentals of nanotech well enough that you can switch between promising career paths. For nanotech that is semiconductors ,quantum dots,electrospun fibers and maybe membranes. But rese...

ITU APT foundation of India workshop April 2025

  #wififorall At the ITU -APT foundation of India workshop  I shared my views with the industry leaders on the benefits of using wifi for offloading  traffic from the G networks giving consumers a simpler ,faster,cheaper and more efficient way of connecting to the internet.  While I agreed with the participants that it is important to unlock more frequency bands as the demand for data continues to rise, I emphasized that it is also essential for network engineers to recycle & reuse the frequency bands to increase the data transfer rates within the same frequency range.  Cellular networks typically create sectors that cover large areas using high power signals increasing the chances of interference. Wifi on the other hand uses low powered devices that rely on small cells to create dense connectivity zones all working in same frequency range. And it works. Nearly every home,every office,every shop has wifi. People are happily using it without reporting any dis...