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. In this work, a heat and mass transfer based mathematical model has been developed and implemented using MATLAB to investigate the drying behaviour of Thompson seedless cylindrical type grapes. Fresh Thompson seedless type grapes having similar size and approximate constant average moisture content were used for the analysis. A laboratory scale experimental test setup has been developed to validate the mathematical model. A two-dimensional transient heat and mass transfer model is developed considering convection, radiation and evaporation phenomenon with different solar radiation inputs. A diffusion-controlled mass transfer model can be considered with change in moisture and temperature. The results obtained from the developed mathematical model can be valuable for predicting accurate temperature, moisture content and drying time and consequently to design, control and optimize the production of dried foods. The maximum reduction of radius of the grape was found to 34.98% at the end of drying process. The moisture of the grapes was decreased from 4.88 to 0.2837 kg of water to kg dry mass.