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The demand and scope of the transport refrigeration system, as a part of the food cold chain, is likely to increase at a tremendous pace in Bangladesh in the coming years. However, the local transport refrigeration sector is mostly based on retrofitting light-to-medium-duty commercial trucks with refrigerated chambers and emphasizing solely on reducing the chamber temperature to a set value. As a result, performance parameters such as appropriate product storage pattern, clearance within the chamber, airflow distribution, uniformity of temperature, etc. are not maintained following any scientific guideline. The proposed study reports the findings of a Computational Fluid Dynamics (CFD) study on the performance of the local refrigerated transport vehicles, with an aim to propose solutions for improving the existing scenario. Using the knowledge obtained from the mapping of the transport-refrigerated vehicles in Bangladesh, a numerical investigation is carried out to examine the effect of commonly followed product storage and stacking patterns on the refrigeration performance. For the typical Bangladeshi product-loading scenario, it is found that a considerable temperature gradient exists within the chamber due to poor airflow distribution, resulting in hot spots in some locations. The study also includes the examination and comparison of the performance improvement opportunity if standard practices reported in an earlier study is employed. Preliminary results are reported with the ultimate objective of developing a standard product-loading pattern suitable and implementable in the local context.

Space exploration and space tourism have now become a raging competition among the developed nations. For this reason, different types of advanced rocket nozzles with prospective privileges are introduced. Altitude adaptive dual bell nozzle will soon replace the conventional nozzles for the first stage rocket launcher. Indeed, this nozzle has auto adaption capability based on altitude. The major feature of a dual bell nozzle is the two bell-shaped contours separated by an inflection point. This nozzle has left rooms for researchers to test different flight conditions and transition characteristics. In this paper, a dual bell nozzle contour has been developed in MATLAB and analysed for different thermodynamic parameters. ANSYS Fluent is used in analysing flow through the nozzle. Shadowgraph imaging technique is used for measuring density gradient and compared it with fluent results. The simulations were performed by using the k-epsilon turbulence model.