This comprehensive review critically examines recent research concerning the application of nanofluids in heat exchangers. The utilization of nanofluids, which are colloidal suspensions of nanoparticles in a base fluid, has garnered significant attention in enhancing heat transfer performance. Various studies have explored the potential benefits and challenges associated with incorporating nanofluids into heat exchanger systems. Through a systematic analysis of recent literature, this review assesses the effectiveness of nanofluids in improving heat transfer efficiency and overall performance of heat exchangers. Key parameters such as nanoparticle concentration, size, and type are thoroughly evaluated to understand their influence on heat transfer characteristics. Additionally, factors such as stability, flow behavior, and thermal conductivity enhancement are scrutinized to provide a comprehensive understanding of nanofluid behavior in heat exchangers. The review also addresses potential limitations and areas requiring further investigation to optimize the utilization of nanofluids in heat exchanger applications. By synthesizing recent findings, this review aims to contribute to the advancement of knowledge in the field of heat exchanger technology and nanofluid applications. Ultimately, the insights provided in this review offer valuable guidance for researchers and engineers seeking to enhance heat transfer processes through the implementation of nanofluid-based heat exchangers. Nanofluids offer advantages like enhanced thermal conductivity and tailored properties, promising optimized heat exchanger designs, leading to energy efficiency and reduced costs. However, challenges remain, such as nanoparticle dispersion and cost-effectiveness, necessitating further research for refinement. Interdisciplinary collaboration is crucial for advancing nanofluid applications, fostering innovation to meet demands for sustainable heat transfer solutions.

This paper investigates heat transfer in a horizontally oriented tubular heat exchanger through a comprehensive examination of both numerical simulations and experimental analyses. The primary focus is on copper as the material of interest, specifically examining an inner tube with a 14 mm internal diameter and 1 mm thickness, as well as an outer tube with a 29 mm external diameter and 1 mm thickness. In addition to these components, two perforated pipes with internal diameters of 11 mm and 20 mm are incorporated; contributing to an overall length of the heat exchanger measuring 281 mm. Notably, the perforation pipe features a 5 mm diameter hole on its periphery. A comprehensive assessment was conducted to appraise heat transfer and coefficients within a straightforward tubular heat exchanger. The mass flow rate of chilled water in the annular space fluctuated between 0.01 kg/sec and 0.11 kg/sec, while the steady flow rate of hot water within the inner tube remained constant at 0.11 kg/sec. Inlet temperatures for the hot water were established at 55 °C, 75 °C, and 85 °C, with the cold water maintaining a consistent inlet temperature of 29 °C throughout the experiment.

Metal matrix composites (MMCs) are attracting automobile and aeronautical sector because of their superior mechanical and physical characteristics which ultimately reduce the weight of components and hence the energy requirements. These composites are prepared by adding various reinforcements into the base metal by the methods like stir casting, squeeze casting, stir and squeeze casting, sand casting, in-setu method, powder metallurgy etc. When more than one particle is added into the base metal; these composites are called as Hybrid Metal Matrix Composites (HMMCs). The machinability of these hard to cut materials is a challenging task in front of manufacturing industry. Present study considers turning operation of HMMC done on either lathe or CNC machine by using different cutting tool materials. This review focuses on effect of various cutting parameters like speed, depth of cut, feed and also the parameters like reinforcement particle type, particle size and weight percentage on the machinability issues like surface roughness, MRR, cutting forces, tool wear etc. Further the various optimization methods used to suggest the cutting parameters to obtain minimum surface roughness, minimum cutting forces, minimum tool wear and maximum Material Removal Rate (MRR) are addressed.

Heat exchanger (HE) is a thermal device used to transfer heat from higher fluid temperatures to lower fluid temperatures. There is an increasing need to increase the efficiency of HEs, develop a wide range of investigations to increase heat transfer rate (HTR), and reduce the size and cost of industrial apparatus in accordance. The current work's goal is to review articles that discuss the main types of tubular heat HEs, factors that affect HTR, and jet impingement in tubular HEs, which are considered among the equipment used in various industries. Researchers have proposed several models of tubular HEs. Many industrial processes, cooling technology, refrigeration equipment, sustainable energy applications, and other fields use tubular HEs. Jet impingement cooling is assumed to be a very efficient method for increasing HT rate, and it has many uses in both the scientific and industrial spheres. This paper's goal is to present an overview of various techniques for improving HT in relation to jet impingement cooling and to define the area of potential future research. This study focuses on a variety of experimental and numerical studies to examine the HT and hydrodynamic behaviour of jet impingement over a range of Reynolds numbers, target surface shapes, distances from the jet plate or nozzle to the target plate, extended jet holes, and the use of nanofluids. Both single jet and multiple jet impingements cooling are included in the current work. The summary of jet impingement for various applications keeps the spotlight on new methods for enhancing HT.

This paper deals with experimental investigations of heat transfer and friction factor characteristics of perforated pin fin heat sink tested in a rectangular channel by using forced convection. Cylindrical pin fins with conical perforations on the lateral surface area were arranged in staggered arrays on the base plate to form heat sink. Two combinations, such as solid fins and fins with conical perforations, were compared. The effect of number of conical perforations and size of conical perforation on thermal performance of heat sink was studied in detail. The heat sinks were subjected to variable air flow rate (10,000 ≤ Re≥ 30,000) in the turbulent regime and constant heat flux input. The results found that with an increase in the number of conical perforations from 2 to 5 results in higher heat dissipation rates and lower pressure drop. With an increase in the size of conical perforation, heat transfer rate initially increases, attains maximum values and then decreases. This is due to the reduction in vertical heat transfer rate through fin by conduction, which shows adverse effects on the overall heat transfer rate by convection. The purpose of using conical perforation instead of circular perforation was to increasethe velocity of air passing through perforation. This affects the turbulence of working fluid at heatsink and ultimately influences heat transfer rate from heat sink.

The thermal concerns, such as capacity loss, uneven temperature distribution and thermal runaway of the battery packs made of lithium-ion batteries (LIB) used in electric vehicles (EV), limits its applicability, especially in situations of high-power demand. This article analyses the causes of heat generation in lithium-ion battery packs, focusing on their dominance over total heat generation. It discusses the thermal issues arising from heat generation, their root causes, and influencing parameters. Further, it examines the effect of cooling systems on peak battery temperature and temperature uniformity, as well as their design, operating, and performance parameters. The review suggests that, when designing a cooling system, entropic heating should be considered alongside Joule heating during low discharge rates and high temperatures, which are the conditions that prevail when an EV cruises on highways in hot weather. Capacity fade of battery is caused by temperature-dependent factors such as the growth of the SEI layer, rise in separator resistance, and active material loss. Hence an effective battery cooling system should maintain a temperature range of 15°C to 35°C and ‘ΔTmax’ below 6°C. Out of the reviewed cooling systems, air cooling is found to be simple and cost effective, but inefficient for large battery packs. PCM based cooling technique offers greater temperature uniformity but is sensitive to melting point. Liquid cooling is most efficient but adds cost and complexity. Evaporative cooling can serve as a middle ground between air and liquid cooling with further research to put it into practice. The future research in battery thermal management may focus lowering the energy consumption of the cooling systems by taking into account, the precise cooling needs as per the modes of battery operation.