Annamalai Mani

Bio: Annamalai Mani is an academic researcher from Indian Institute of Technology Madras. The author has contributed to research in topics: Injector & Heat transfer. The author has an hindex of 19, co-authored 62 publications receiving 1096 citations. Previous affiliations of Annamalai Mani include Indian Institutes of Technology & Presidency University, Kolkata.

Experimental studies on thermal spray-coated horizontal tubes for falling film evaporation in multi-effect desalination system

Abstract: Multi-effect distillation is an important principle in desalination technology, in which the thin film evaporation of sea water takes place at the outer surface of bundle of tubes, normally arranged in horizontal. Heat of condensation inside the tube is transferred to the falling water film by conduction, thereafter convective evaporation of film takes place. Heat transfer on the outside is unpredictable due to the uncertainty in nature of film, film thickness, film dryout, etc. and film coefficient is considerably less compared to inside. Thermal spray coating on metallic surface with molten metal particles create porous surface which enhances heat transfer due to higher turbulence and nucleation sites, if sufficient temperature difference available. This paper discusses the experimental studies carried out on a 3 × 5 bundle of 25.4 mm ∅ Al horizontal tubes with thermal spray coating of aluminum. Influences on temperature profile, heat transfer coefficient, mass evaporation, etc. are studied. A c...

Comparison of Conventional and Open Flat Plate Collectors for Evaporation of Tannery Effluent

Abstract: An experimental study has been made to augment evaporation of tannery effluent (soak liquor) and compare the performance of the conventional fibre reinforced plastic (FRP) flat plate collector with an open FRP flat plate collector. As the tannery effluent flows over FRP flat plate collectors in the form of thin film, the effluent is heated by gaining heat from the absorber due to exposure to solar radiation. Hence, the partial pressure at the interface of the effluent increases, resulting to increase in pressure difference between the interface and air. Thus, leading to increase in mass transfer rate. In this paper, performance comparison is made between the FRP open flat plate collector and the conventional FRP flat plate collector, to understand the effect of climatic conditions, concentration and mass flow rate of the effluent. This study shows that the conventional FRP flat plate collector gives better performance than the open FRP flat plate collector.

Effect of Various Nozzle Profiles on Performance of a Two Phase Flow Jet Pump

Abstract: This paper reports on the results of experimental investigations on the performance of a jet pump ope rated under selected primary flows to optimize the related para meters For this purpose a two-phase flow jet pump was used employing various profiles of nozzles as the primary device which was designed, fabricated and used along with the combination of mixing tube and diffuser The profiles employed were circular, coni cal, and elliptical The diameter of the nozzle used was 4 mm The area ratio of the jet pump was 016 The test facility created for this p urpose was an open loop continuous circulation system Performance of the jet pump was obtained as iso-efficiency curves on characteristic curves drawn for various water flow rates To perform the suction ca pability, evacuation test was conducted at best efficiency po int for all the profiles Keywords—Evacuation test, jet pump, nozzle profile, nozzle spacing, performance test, two phase flow I INTRODUCTION HE jet pump transfers momentum and energy from a high velocity jet to a secondary fluid The good sealing possibilities and the absence of moving parts are t he merits of jet pump Jet pumps are widely used because of thei r high reliability where efficiency is of secondary import ance, particularly in remote or inaccessible locations, s uch as for flash desalination systems to create a vacuum insid e the flash chamber, pumping corrosive or erosive mixtures where air may be present in the suction line, and the offset- installation which is a unique feature of jet pump To evaluate the performance, a two-phase flow jet pump was tested Water from an open tank was pressurized by a multistage h orizontal axis centrifugal pump having variable frequency dri ve As high pressure motive fluid was supplied through the nozzle, pressure energy was converted into kinetic energy This flow then combined with the low velocity suction fluid r eaching the suction chamber of 50 mm diameter by turbulent mixing in the mixing tube of the pump The diameter and length of mixing tube were 10 mm and 262 mm respectively In order to convert partly the velocity head into pressure head , this resultant flow was further delivered through a diff user

Heat and Fluid Flow Characteristics of Copper Metal Foam as Heat Pipe Wick Material

Abstract: This work is carried out to study the copper metal foam as porous wick structure in a flat heat pipe. The method of fabricating copper foam has been described. The characterization of copper foam has been carried out by scanning electron microscope (SEM) and X-Ray Diffractogram (XRD) analysis. Effect of liquid velocity on pressure drop and maximum capillary heat transport of fabricated copper foam has been presented.

Ejector refrigeration: A comprehensive review

Abstract: The increasing need for thermal comfort has led to a rapid increase in the use of cooling systems and, consequently, electricity demand for air-conditioning systems in buildings. Heat-driven ejector refrigeration systems appear to be a promising alternative to the traditional compressor-based refrigeration technologies for energy consumption reduction. This paper presents a comprehensive literature review on ejector refrigeration systems and working fluids. It deeply analyzes ejector technology and behavior, refrigerant properties and their influence over ejector performance and all of the ejector refrigeration technologies, with a focus on past, present and future trends. The review is structured in four parts. In the first part, ejector technology is described. In the second part, a detailed description of the refrigerant properties and their influence over ejector performance is presented. In the third part, a review focused on the main jet refrigeration cycles is proposed, and the ejector refrigeration systems are reported and categorized. Finally, an overview over all ejector technologies, the relationship among the working fluids and the ejector performance, with a focus on past, present and future trends, is presented.

Ejectors: applications in refrigeration technology

Abstract: This paper provides a literature review on ejectors and their applications in refrigeration. A number of studies are grouped and discussed in several topics, i.e. background and theory of ejector and jet refrigeration cycle, performance characteristics, working fluid and improvement of jet refrigerator. Moreover, other applications of an ejector in other types of refrigeration system are also described.