http://localhost:8080/xmlui/handle/123456789/7042 Sun, 12 Apr 2026 02:12:35 GMT 2026-04-12T02:12:35Z http://localhost:8080/xmlui/handle/123456789/7051 CFD analysis on vortex tube CHAUHAN, RAYBAHADURSINH Present work has focused on the energy separation and flow field behavior of a vortex tube by utilizing both straight and helical nozzles. Three kinds of nozzles set include of 3 and 6 straight and 3 helical nozzles have been investigated and their principal effects as cold temperature difference was compared. The studied vortex tubes dimensions are kept the same for all models. The numerical values of hot and cold outlet temperature differences indicate the considerable operating role of helical nozzles, even a few numbers of that in comparing with straight nozzles. The results showed that this type of nozzles causes to form higher swirl velocity in the vortex chamber than the straight one. To be presented numerical results in this paper are validated by both available experimental data and flow characteristics such as stagnation point situation and the location of maximum wall temperature as two important facts. These comparisons showed reasonable agreement. For Full Thesis Kindly contact to respective Library Wed, 01 May 2013 00:00:00 GMT http://localhost:8080/xmlui/handle/123456789/7051 2013-05-01T00:00:00Z http://localhost:8080/xmlui/handle/123456789/7050 Performance and Emission Measurement of Diesel fired Boiler using Diesel and Palm biodiesel blends Khiraiya, Krunal Biodiesel is widely accepted as comparable fuel to diesel in compression ignition engines and Diesel fired boiler. It offers many advantages including; higher cetane number, reduced emissions of particulates, CO, NOX, and hydrocarbons, reduced toxicity, improved safety and lower lifecycle CO2 emissions. A characteristic of bio-diesel limiting its application is its relatively poor low-temperature flow properties. Improvement of its low-temperature flow characteristic still remains one of the major challenges when using biodiesel as an alternative fuel for Diesel fire boiler. The bio-diesel fuels derived from fats or oils compounds display higher cloud points and pour points thus limiting their application. The objective of this research was to determine the relationship between Diesel fired boiler performance and emissions using diesel, volumetric blends of palm oil biodiesel and diesel as a fuel in a diesel fired vertical coil type, water tube, and non IBR boiler. Boiler efficiency with B25, B50, B75 and B100 fuels are 62.73%, 62.45%, 62.36% and 62.32% respectively, which are higher compared to 62.39% of diesel. Maximum brake thermal efficiency with B100 fuel is found 64.98%, which are lower compared to 65.30% with diesel. The higher kinematic viscosity of B100 results in larger droplet diameter and hence in lower brake thermal efficiency. Maximum EGT measure for diesel, B25, B50, B75 and B100 fuels are 300°C, 295 °C, 308°C 328°C and 340 °C respectively at 11 bar fuel pressure. Except B20, other blends shows higher EGT compared to diesel fuel. Minimum emission of CO with diesel, B25, B50, B75 and B100 fuels are 0.037 %/Vol., 0.0336 %/Vol., 0.0326 %/Vol., 0.033%/Vol. and 0.036 %/Vol. respectively at fuel pressure of 11 bar. Among all compared fuels, CO emission for B50 is lowest followed by B25, diesel and B100. At maximum fuel pressure, emission of CO with diesel, B25, B50, B75 and B100 fuels are 0.0605 %/Vol., 0.0616 %/Vol., 0.0605 %/Vol., 0.060%/Vol. and 0.05 %/Vol. respectively. CO emission with B100 fuel is 21% higher compared to diesel fuel. Highest HC emissions for diesel, B25, B50, B75 and B100 fuel are 18 ppm, 16 ppm, 14 ppm, 13ppm and 12 ppm respectively at no load. While using B100 fuel emission of HC reduces approximately half the value of HC emissions using diesel fuel. For Full Thesis Kindly contact to respective Library Wed, 01 May 2013 00:00:00 GMT http://localhost:8080/xmlui/handle/123456789/7050 2013-05-01T00:00:00Z http://localhost:8080/xmlui/handle/123456789/7049 Experimental determination & simulation of heat transfer rate for twisted tapes in double pipe heat exchanger CHAUDHARI, ANUP This exchanger usually consists of two concentric pipes with the inner pipe One fluid flows in the inner pipe and the other fluid flows in the annulus between pipes in a counter flow direction for the ideal highest performance for the given surface area. However, if the application requires an almost constant wall temperature, the fluids may flow in a parallel flow direction. This is perhaps the simplest heat exchanger. Flow distribution is no problem, and cleaning is done very easily by disassembly. This configuration is also suitable where one or both of the fluids is at very high pressure, because containment in the small-diameter pipe or tubing is less costly than containment in a large-diameter shell. The working fluid is water at atmospheric pressure. Hot water is supplied to the inner tube stream by using hot water pump. Cold water is being circulated in the annular space of double pipe heat exchanger through gravity pressure by using over head water tank. when using twisted tape in double pipe heat exchanger experimental obtained results are validated with results obtained by CFD analysis. Experimental results are found in good agreement with results obtained from CFD in counter fluid flow arrangements. For Full Thesis Kindly contact to respective Library Wed, 01 May 2013 00:00:00 GMT http://localhost:8080/xmlui/handle/123456789/7049 2013-05-01T00:00:00Z http://localhost:8080/xmlui/handle/123456789/7048 Performance Evaluation of Heat Transfer Rate in Automobile Radiator Using Nanoparticles Bhoi, Ramesh Continuous technological development in automobile industries has increased the demand for high efficiency engines. A high efficiency engine is not only based on its performance but also for better fuel economy and less emission. Reducing a vehicle weight by optimizing design and size of a radiator is a necessity for making the world green.There are several different approaches and any one of these can take to optimize the heat transfer performance of radiator design. These include:  Changing the fin design,  Changing the tube type,  Changing the flow arrangement,  Changing the fin and tube material,  Changing the fluid. Heat transfer fluids have inherently low thermal conductivity that greatly limits the heat exchange efficiency. While the effectiveness of extending surfaces and redesigning heat exchange equipment to increase the heat transfer rate has reached a limit, many researchers made an attempt to improve the thermal transport properties of the fluids by adding more thermally conductive solids into liquids. Liquid dispersions of nanoparticles, which have been termed “nanofluids”, exhibit substantially higher thermal conductivities than those of the corresponding base fluids. In dissertation work using four stroke four cylinder engine as a experimental set up. In this project, different proportions of Al2O3 nanoparticles by weight have been added to conventional fluid (water), and based on that the enhancement in heat transfer rate has been found out by taking readings & calculating heat transfer rate. For Full Thesis Kindly contact to respective Library Wed, 01 May 2013 00:00:00 GMT http://localhost:8080/xmlui/handle/123456789/7048 2013-05-01T00:00:00Z