Drying food to preserve it is an energy-intensive process. Solar drying is one of the oldest methods used to preserve agricultural produce. The open sun drying can cause the degradation of the quality and quantity of the product and also it takes long time for drying. This technique is modified by using several technologies like solar air dryer. Solar thermal energy has tremendous potential for commercial and industrial drying applications with air temperatures as high as 80 degrees Celsius. The main objective of this research work is to examine the physical changes that occur during convective air-drying process of Thompson seedless type cylindrical grapes through experimental and numerical work. These include changes in the physical properties of the product, such as the moisture content, the temperature of the product, and the size of the product. The objective of developing mathematical model is to develop a universal diffusion model of drying kinetics that can be applied to a variety of shrinkable products such as fruits and vegetables are in cylindrical shape. Developed a one and two-dimensional transient diffusion model that takes into account convection, radiation, and evaporation phenomena under a variety of operating conditions for simulating grape drying and shrinkage. The dryer was tested at varying ambient temperature and solar radiation conditions to evaluate the performance. The experimental trial was done for the validation of the mathematical model. This mathematical model was developed by the integration of different models for predicting the performance of solar dryers, particularly for Thomson seedless grapes of cylindrical shape. A cabinet-type double-glazed solar dryer with a length of 2 m, a width of 1 m, and a height of 0.8 m that is installed in Pune, India and used for the experimental trails. Experimental tests was conducted for different ambient temperatures and different solar radiations, and rates of dehydration and reduced drying time were recorded in comparison to the tests conducted. The results obtained from the mathematical model are compared with experimental results and found to be in agreement with a maximum error of 14%. The dryer was tested at varying ambient temperature and solar radiation conditions to evaluate the performance. Around 15 kg of fresh grape with initial moisture percent of 86-88% on wet basis were kept in the natural convection dryer (10.00 AM – 5.00 PM). At the end of the test, the moisture percent of the grape was reduced to 13-14% for the tests conducted.