Faculty Publications
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Item Performance Prediction Model Development for Solar Box Cooker Using Computational and Machine Learning Techniques(American Society of Mechanical Engineers (ASME), 2023) Anilkumar, B.C.; Maniyeri, R.; Anish, S.The development of prediction models for solar thermal systems has been a research interest for many years. The present study focuses on developing a prediction model for solar box cookers (SBCs) through computational and machine learning (ML) approaches. The prime objective is to forecast cooking load temperatures of SBC through ML techniques such as random forest (RF), k-nearest neighbor (k-NN), linear regression (LR), and decision tree (DT). ML is a commonly used form of artificial intelligence, and it continues to be popular and attractive as it finds new applications every day. A numerical model based on thermal balance is used to generate the dataset for the ML algorithm considering different locations across the world. Experiments on the SBC in Indian weather conditions are conducted from January through March 2022 to validate the numerical model. The temperatures for different components obtained through numerical modeling agree with experimental values with less than 7% maximum error. Although all the developed models can predict the temperature of cooking load, the RF model outperformed the other models. The root-mean-square error (RMSE), determination coefficient (R2), mean absolute error (MAE), and mean square error (MSE) for the RF model are 2.14 (°C), 0.992, 1.45 (°C), and 4.58 (°C), respectively. The regression coefficients indicate that the RF model can accurately predict the thermal parameters of SBCs with great precision. This study will inspire researchers to explore the possibilities of ML prediction models for solar thermal conversion applications. © © 2023 by ASME.Item AN ITERATIVE ALGORITHM FOR DESIGNING AND SCALING OF PARABOLIC TROUGH COLLECTOR BASED SOLAR AGRO-DRYING SYSTEM(Begell House Inc., 2025) Kabeer, V.P.A.; Maniyeri, R.; Anish, S.This work proposes a simple and robust iterative algorithm for designing and scaling an indirect solar agro-drying system, which harvests thermal energy for drying using a parabolic trough collector (PTC). Separate computational procedures are developed for the design of the PTC by considering receiver tubes with and without a glass envelope. The computational procedure starts with the total heat requirement in the drying chamber and considers various heat losses and heat loss coefficients for the PTC receiver tube. The equations for various modes of heat losses in receiver tubes with and without a glass envelope are identified and formulated. Using thermal network and heat balance analysis, the expressions for various heat losses and overall heat loss coefficient are formulated in both cases. Required aperture area for the reflector surface of the PTC can be obtained in terms of overall heat loss coefficient and the collector heat removal factor. The tedious equations involved in computational procedure are solved using an iterative algorithm by developing a code in MATLAB. The results obtained from parametric analysis conducted using computational procedure reveals that heat losses and area of PTC required for providing drying thermal energy will be more if the receiver tube of PTC is without glass cover. The iterative algorithm described here can be used to optimize the design parameters and thus helps researchers in designing and sizing the components required for drying agro-based products. The algorithm will also help to scale the size of PTC and drying chamber based on the quantity and item to be dried. © 2025 by Begell House, Inc.Item Multi-criteria decision-making techniques based optimum selection of phase change material and its implementation in a solar crop dryer for agricultural products(Elsevier Ltd, 2025) Kabeer, V.P.A.; Maniyeri, R.; Anish, S.The energy storage in solar thermal systems is crucial as the fluctuations in solar energy and its unavailability in the night periods adversely affects the system effectiveness. The proper selection of phase change material (PCM) for energy storage in a particular application is vital important as it directly affects the overall performance of the system. The selection of an optimum PCM for a specific application is a complex problem, requiring consideration of multiple criteria involving thermal, economic, environmental and physical aspects. The present study aims to select the optimum PCM for energy storage in a solar crop dryer, while being sustainable and cost-effective. The organic PCM alternatives with their melting temperature in the range suitable for crop drying application are selected for the study. Six widely recognized multi-criteria decision-making (MCDM) methods viz. EDAS, MOOSRA, TOPSIS, PROMETHEE, MOORA and CODAS have been employed to identify the most suitable PCM from the available alternatives. The criteria weights for optimization are determined using AHP, CRITIC and ENTROPY techniques, and their combinations. All MCDM techniques gives paraffin wax as the optimum PCM to be used as energy storage material in solar dryer. The average scores such as TOPSIS: 0.75, EDAS: 0.82, MOOSRA: 0.94, MOORA: 0.36, CODAS: 0.13 and PROMETHEE: 0.094 are obtained for paraffin wax, and are found to be highest compared with other alternatives. The sensitivity analysis carried out with weight variation method ensures the robustness and reliability of applied methods. Further, a simplified iterative computational procedure is developed to compute the required quantity of PCM and its container dimension to maintain the drying temperature for a specific duration during off-sun shine hours. The computational procedure also selects paraffin wax as the best PCM, as its required quantity is less and thus container size is small. The experimental investigation on the solar dryer, incorporating paraffin wax as the thermal storage material exhibits good agreement with the computational procedure, thereby substantiating the effectiveness of the PCM selection methodology. The paraffin wax in its optimum quantity could deliver the heat at a constant temperature of nearly 60 °C for six hours, during sun down hours and night (from 3.00 pm to 9.00 pm), which supports the PCM selection using MCDM techniques and agrees with findings of computational procedure. The absorber temperature is also able to be maintained above 50 °C for an extended period of six hours. The average air temperature of 45 °C is maintained in the dryer during the sun-down period (3.00 pm to 9.00 pm), using paraffin wax as energy storage material. With the highest benefit-cost ratio of 8.17, paraffin wax also emerged as the most cost-effective option among the PCM alternatives. © 2025 Elsevier LtdItem Design of thermal energy storage system for solar cooker: a review(Springer, 2025) Anilkumar, B.C.; Maniyeri, R.Solar cooking has been a research focus worldwide over the last few decades due to its numerous advantages, such as no running costs, non-polluting nature and ample availability. Solar cookers incorporate thermal energy storage (TES) units to enable cooking during off-sunshine hours. Within solar thermal applications, latent heat storage materials (LHSMs), particularly phase change materials (PCMs) are increasingly vital due to their superior energy storage density and isothermal working properties. The present review aims to provide a comprehensive overview of various TES unit designs integrated with cooking vessels for solar cookers. We discuss different types of solar cookers, various TES unit configurations, and the thermo-physical properties of heat storage materials. A key aspect of this work involves comparing the sizes of various TES units, derived from our previously developed computational scheme, with existing research. Prior studies often lacked specifics on the duration of off-sunshine cooking. However, determining the optimal PCM mass is crucial for designing efficient LHS units that maximize heat storage and release for sustained cooking. To address this gap, we employed a computational procedure to determine the duration for which various LHS units, integrated with box-type solar cookers, can maintain a constant cooking temperature. We also identified and compared the dimensions of containers needed to hold the optimum PCM mass. Our computational findings for the outer vessel diameter of LHS units align closely with previous studies. This computational approach offers a robust methodology for developing TES units that optimize PCM latent heat utilization, significantly enhancing solar cooker performance during sundown hours. Ultimately, we propose a pathway for improving future TES unit designs and present a strategy for marketing solar cookers. This review will be an invaluable resource for researchers, stimulating further advancements in solar cookers integrated with TES systems. © Indian Academy of Sciences 2025.