Journal of Modern Thermodynamics in Mechanical System

Effects of Sensitization Temperatures on the Microstructure, Ferrite Count and Corrosion of Austenitic and Ferritic Stainless Steel in Marine Environment

Wed, 18 Mar 2026 00:00:00 +0000

The study investigated the effect of the sensitisation temperatures on the microstructure, ferrite count and corrosion of austenitic and ferritic stainless steel in a marine environment. Austenitic stainless steel with 16.43% Cr, 9.72% Ni and 2.10% Mo and ferritic stainless steel with 16.51% Cr and 0.12% Ni were used for the study. An X-ray Fluorescent, Oxford Instrument XMET 7000, was used to identify the metals. A total of ten specimens were prepared for the study, five ASS 316 and five FSS 430, with one sample of both specimens set aside as the as-received sample. The Leeb hardness, ferrite count and tensile strength of the specimens were determined before they were subjected to sensitisation and accelerated linear polarisation resistance (LPR) corrosion test. Specimens were also subjected to a surface scan to determine their microstructure. The ASS 316 was observed to have experienced major weight loss when sensitised to 700°C, while the FSS 430 specimen only experienced slight weight loss. The ferrite count for ASS 316 specimen reduced greatly when sensitised to 700°C, and for FSS 430 at 600°C. The Leeb hardness test revealed very hard specimens at 600°C, and decreases with an increase in temperature. Worthy of note is the increase in corrosion rate as the immersion time increases. The rate of corrosion is higher for FSS 430 as compared to the ASS 316 specimen. The micrographs revealed chromium-depleted zones for the ASS 316 are higher for sensitisation temperatures of 500°C and 600°C. While the FSS 430 specimens revealed chromium, depleted zones increased with an increase in the sensitisation temperature.

Design and Experimental Evaluation of a Smart Automotive Air Conditioning System with Adaptive Thermal Control for Passenger Vehicles

Amol More — Tue, 17 Mar 2026 00:00:00 +0000

Modern vehicle systems must prioritise passenger comfort and energy efficiency, especially in the face of fluctuating operational and climatic conditions. Traditional vehicle air conditioning (AC) systems use manual settings or fixed control logic, which frequently leads to fluctuating cabin temperatures, excessive compressor operation, and increased energy usage. The adaptive thermal control-based smart automobile air conditioning system for passenger cars is designed, built, and experimentally evaluated in this study. The suggested system incorporates cabin temperature, ambient temperature, and high- and low-pressure sensors for real-time monitoring. It uses a vapour compression refrigeration cycle with an expansion valve arrangement. By dynamically adjusting compressor engagement and refrigerant flow in response to changes in thermal load, a sophisticated control algorithm reduces needless cycling and boosts system efficiency. Standard assembly techniques, specialised hose routing, and optimum component selection were used to create the system. Vacuum testing and R134a charging were then conducted. In comparison to conventional systems, experimental results show improved temperature stability, a lower compressor duty cycle, a faster cooling reaction, and increased operational reliability. For passenger cars, electric and hybrid platforms, and intelligent automotive thermal management applications, the proposed system provides an affordable and retrofit-friendly solution.

Simulation and Experimental Analysis of Mechanical Testing Effects on Electrical Parameters of Lithium-ion Batteries across Different Form Factors for Battery Life Prediction and Accident Prevention

Mon, 06 Apr 2026 00:00:00 +0000

Safety and reliability of Lithium-ion batteries (LIBs) are paramount, particularly in a scenario where mechanical abuse causes catastrophic failure. This study employs the analysis of electrical results with different types of mechanical abuse, including compression, impact, puncture and vibration on cylindrical, prismatic and pouch cells of LIBs. The idea is to make a transition from mechanical stress and relate it to such electrochemical characteristics as internal resistance, capacity loss, voltage swing, and thermal effects. The experimental procedure is supported by the finite element modeling (FEM) to study the detailed structural deformations, failure propagation, and degradation phenomena. This type of monitoring is especially significant for identifying short-circuit behavior and thermal runaway prognosis, as well as analyzing performance degradation modes during mechanical abuse testing. This is a follow-up of a previous study exploring predictive modeling for the determination of the operational life of LIBs under realistic mechanical stress. Nevertheless, our work extends the prospects of ME-mechanisms and the consequences in LIBs in line with the development of safe and reliable battery structure, benchmarking, and management. The results that would be derived from such investigations would be useful in electric vehicles, aerospace, and renewable energy storage, where the battery’s life with respect to mechanical stress is paramount.

Performance Analysis of Square Port Microchannel Condenser using various Nanofluids in Refrigeration System

Yashodhan V Patil, Mukund L. Harugade — Tue, 17 Mar 2026 00:00:00 +0000

Air-conditioning and refrigeration applications are critical in the domestic, commercial and industrial systems, which include food preservation, medical storage and thermal control of electronic systems. There is a need to make these systems more energy efficient to minimise the use of electricity and increase environmental sustainability. Effective heat transfer in the condenser and evaporator is important in the performance of a vapour compression refrigeration (VCR) system. In recent times, the use of microchannel heat exchangers and nano-refrigerators has become a viable strategy to improve the performance of the heat transfer. This is experimental research as it involves the determination of the impact of nanoparticles on the performance of the VCR system using TiO₂ and Al₂O₃ nanoparticles at 2 g and 3 g concentrations, respectively, with a constant refrigerant flow rate of 10 LPH. Performance measurement was done on the cooling capacity (Q₀), compressor work (Wc), and coefficient of performance (COP). It was experimentally found that nanoparticles led to a significant increase in the thermodynamic efficiency of the refrigeration system relative to that of the base refrigerant. The cooling effect was directly proportional to the concentration of nanoparticles, and the maximum cooling effect was realised at 3 g TiO₂ nano-refrigerant. On the same note, the cop values of all nano refrigerant cases recorded higher values compared to the pure refrigerant, with the highest average cop values recorded with 3 g TiO₂ and then 3 g Al₂O₃. The COP was improved primarily because of the rise in the refrigeration effect, and not because a significant decrease in compressor work was achieved. Moreover, the nanoparticle concentration between 2 g and 3 g had a positive effect on the performance of the system, which validates the importance of nanoparticle concentration in enhancing the performance of the heat transfer system. In general, the findings show that nano-refrigerants and especially TiO₂ nano-refrigerants can remarkably improve the efficiency of the vapour compression refrigeration systems without necessarily impacting negatively on the system’s operation. These results demonstrate the promise of nano-refrigerants as an effective material in enhancing thermal conditions and energy efficiency in contemporary refrigeration and HVAC systems.

Experimental Evaluation of Steam Dryness Fraction Using a Separating Calorimeter with Uncertainty Consideration

Fri, 08 May 2026 00:00:00 +0000

Steam quality plays an important role in determining the performance and reliability of thermal systems. In the present study, the dryness fraction of steam is experimentally evaluated using a separating calorimeter under varying pressure conditions ranging from 1 to 2 kg/cm². The experimental method involves mechanical separation of moisture followed by measurement of the separated water and condensed steam in the condenser. The measured dryness fraction varies between 0.882 and 0.933, which indicates high-quality steam conditions. But due to the limitation of incomplete separation of fine moisture particles, a correction model is applied to improve the accuracy of the results. The corrected dryness fraction values show a marginal increase of approximately 0.5 to 0.9%. Graphical analysis is performed to study the variation of dryness fraction, error, and moisture content with pressure. The results show fluctuations due to transient operating conditions and measurement uncertainties. The study demonstrates that while the separating calorimeter is a simple and cost-effective tool, its accuracy depends significantly on experimental conditions and requires correction for reliable estimation of steam quality.