Bajirao Gawali

• Doctor of Mechanical Engineering
• Professor (Full) at Walchand College of Engineering, Sangli

Stirling machines are ecologically propitious refrigeration devices that utilize natural gases like helium, nitrogen, or air. Stirling machines are active refrigerators that should be designed with minimal vibrations and durability in order to fulfil current and future commercial de-mands and requirements. The present paper deals with the modificat...

In this study, a simplified analytical model based on evaporative cooling theory is developed to investigate the coupled heat and mass transfer processes in a direct contact counter flow forced draft cooling tower. The complex sets of differential equations are simplified to linearized differential form and solved using the initial boundary value p...

In this paper, an experimental investigation of heat transfer and fluid flow analysis of rectangular mini channel array under steady flow condition is carried out. The channel dimensions are selected in such a way that, flow within the channel is maintained hydro dynamically developed and thermally developing. This type of flow gives enhancement in...

The world is facing the problems of the energy crisis. Thermal analysis and energy conservation of the engineering devices help to improve their performance. This paper conducted an experimental investigation for the performance analysis and exergy assessment of an Inertance Pulse Tube Cryocooler (IPTC) that uses working fluid -helium operated betw...

In this study, a simplified thermal model is developed for coupled heat and mass transfer processes in a packed tower counter flow adiabatic dehumidifier and regenerator. The developed differential energy and mass conservation equations are simplified to first-order linear differential form and solved using the boundary value problem to predict the...

Organic Rankine Cycle (ORC) has consistently been demonstrated to be one of the most effective and reliable methods for extracting low-grade waste heat energy. The objective of this study is to analyze the integrated vapor compression refrigeration system (VCRS)-ORC system. A custom and verified dynamic model is built using MATLAB-Simulink. The met...

Energy is the ability to cause a change in a system. It is usually available as exergy and anergy. Exergy is a useful part of energy, also known as available energy. Anergy is the counterpart of exergy, also known as unavailable energy. Thermodynamics is the science associated with energy and exergy, thereby ensuring both laws of thermodynamics—the...

The oscillating flow heat transfer (OFHT) has been an area of interest to researchers for the last four decades due to the substantial improvement in the performance of such devices. The present paper reviews oscillatory flow heat transfer in detail by considering the type of interaction medium, design, and applications as essential criteria. This...

India is the world's ninth-largest grape-producing country. Maharashtra is a major producer of grapes and raisins, with the Sangli district accounting for a large portion of the total, hence becoming the area of focus of this research. Sangli becomes an important location for grape production. The objective of this research is to conduct a thorough...

Stirling machines are ecologically propitious refrigeration devices that utilize natural gases like helium, nitrogen, or air. Stirling machines are active refrigerators that should be designed with minimal vibrations and durability in order to fulfil current and future commercial de-mands and requirements. The present paper deals with the modificat...

The use of lower global warming potential refrigerants as an alternative to hydrochlorofluorocarbons and hydrofluorocarbons from an environmental perspective is the need of an hour. The feasibility and possibility of alternative refrigerants in the existing refrigeration system can be recognized using exergy assessment. This will lead to improving...

The increased use of fossil fuels in the industry has resulted in severe environmental issues, such as ozone depletion, air pollution, and climate change, among others. Due to diverse resources, such as biomass, solar radiation, and so on, approximately half of the energy produced worldwide is discarded as heat. Utilizing this waste energy as heat...

Stirling-type Pulse Tube Cryocoolers (PTC) are designed to meet present and upcoming commercial requirements and needs with durability and low vibrations. Multistaging in Stirling type PTC is one of the major developments reported in recent times for low-temperature achievement, due to improved performance over a period of time. The current study a...

The inertance type pulse tube refrigerator (IPTR) has been extensively used in industries due to its small size and efficiency. The physical phenomena of oscillating flow in IPTR is complex and it can be examined by using a commercial computational fluid dynamics (CFD) software. Researchers are not so much interested in the 3D analysis of IPTR due...

The manufacture of cement is highly energy-intensive and emission-intensive due to the large heat needed for plant. Nitrus Oxide (N2O) is one of the major greenhouse gas emitted into the atmosphere through it. The purpose of this work is to reduce NOX emissions inside calciner by using air staging and raw meal split technology. Tertiary air staging...

From the last century, the demand for energy is increasing at a significant rate. So, there is a requirement of new energy sources that will meet the current energy demand. The best solution for this problem is developing such a technology that will convert the low-grade heat, i.e., industrial waste heat to high-grade energy through the Organic Ran...

In the present work, an experimental investigation of heat transfer enhancement parameters of the oscillating flow heat exchanger using Kurzweg’s and Nishio’s correlations is carried out. An oscillatory axial movement of fluid is established within the flow tube using piston cylinder mechanism. The experiments are carried out for seven different fr...

In the present work an experimental investigation of heat transfer enhancement parameters of the oscillating flow heat exchanger under different frequencies, tidal displacement and heat fluxes is carried out. The effect of different parameters on experimental effective thermal conductivity and convective heat transfer coefficient in cooling region...

Microscale heat exchangers are becoming an important area of interest in many fields of developing technology that require compact high heat energy removal solutions. In our work, numerical and experimental analyses are carried out for rectangular microchannels with five sets of rectangular configurations, in order to find optimum configuration of...

Nowadays linear motor compressors are commonly used in miniature cryocoolers instead of rotary compressors because rotary compressors apply large radial forces to the piston, which provide no useful work, cause large amount of wear and usually require lubrication. Recent trends favour flexure supported configurations for long life. The present work...

Investigation of heat transfer characteristics has been carried out by theoretically and experimentally for a straight microchannel heat sink of rectangular cross section of 507µm hydraulic diameter with water as the circulating fluid. The temperature distribution, pressure drop, heat transfer coefficient and total thermal resistance of the heat si...

Energy consists of two parts, one is available energy and other is unavailable energy. The available energy is useful part of energy from which maximum useful work is obtained which is known as exergy. Unavailable energy accounts for the losses and irreversibility's occurring in the system.Exergy analysis is an assessment technique for systems and...

Experimental and numerical analysis were performed to evaluate heat transfer characteristics of water through five sets of rectangular microchannels. Microchannels of hydraulic diameter of 222 μm, 267 μm, 323 μm, 330 μm and 343 μm respectively for Re number between 2.1 to 48 were analysed. Numerical analysis and experiments were conducted under a i...

Electricity saved is electricity generated." In today"s scenario, our country is facing challenges of saving electricity. Requirement of energy efficient devices is of utmost importance in view of futuristic energy requirements. The use of electricity in household appliances such as refrigerator is obvious. It has been observed that, refrigerators...

This paper describes the CFD analysis of single rectangular microchannel for hydraulic diameter 319 μm. While CFD analysis the Nusselt number observed is 4 to 5 with different Reynolds Number variation for flow rate of 0.001 kg/sec to 0.012 kg/sec. The current work describes CFD analysis of single microchannels for length of 50 mm with water as a f...

This paper describes the CFD analysis of single rectangular microchannel for hydraulic diameter 319 μm. While CFD analysis the Nusselt number observed is 4 to 5 with different Reynolds Number variation for flow rate of 0.001 kg/sec to 0.012 kg/sec. The current work describes CFD analysis of single microchannels for length of 50 mm with water as a f...

A numerical optimization tool is used to optimize forced convection micro-channel for minimum channel depth, channel width for high heat flux and low pressure drop. Electronic chip size of 30mm × 25mm is analyzed under forced convection heat transfer by considering rectangular channel geometry parameters with no phase transition. Channel physical p...

Thermal energy storage using phase chase materials (PCM) has received considerable attention in the past two decades for time dependent energy source such as solar energy. From several experimental and theoretical analyses that have been made to assess the performance of thermal energy storage systems, it has been demonstrated that PCM-based system...

In this study, the experimental and numerical investigation of forced convective heat transfer in an optimized rectangular micro-channel heat sink (MCHS) is analyzed using water as the working fluid. The optimization of MCHS has carried out by using CVM (Constant Volume Method) and VVM (Variable Volume Method). From the optimization, it is clear th...

Micro-convection is a strategic area in transport phenomena, since it is the basis for a wide range of miniaturized high-performance pplications. Surface area is one of the important concepts for high flux heat transfer in Microchannel performance. Microchannel with hydraulic diameters 440μm, 476μm, 500μm and 550μm are analyzed for optimize microch...

Theoretical model based on cyclic analysis has been extended to design the integral pulse tube cryocooler. Cryocooler is developed to match with the indigenously developed opposed piston linear compressor of 30 cc swept volume. The design is carried for the Stirling type Pulse Tube cryocooler to develop 15 W at 70 K. The Pulse Tube cryocooler has b...

The design of an Orifice Pulse Tube (OPT) Cryocooler has been validated and applied for the design of Inertance Pulse Tube (IPT) Cryocooler with 15 W at 70 K. Parametric analysis based on cyclic simulation model has been used as a design tool. This model begins with the estimates of the ideal refrigerating effect and ideal power requirement. Differ...