Asphalt concrete(Ascon) is used to repair potholes and cracks. Special truck-mounted cargo boxes transport 200℃ asphalt concrete to repair potholes and cracks. However, long working and transportation hours to repair wide roads decrease the temperature of the asphalt concrete inside the cargo boxes. If the asphalt concrete temperature drops below 170℃, the adhesion with roads that need repair decreases. Therefore, the temperature of the asphalt concrete needs to be maintained for a long time. Conventional asphalt concrete cargo boxes are mostly burner-type models using hot air to prevent the temperature of the asphalt concrete from dropping. However, there are significant temperature differences between the asphalt concrete near and far away from the hot air, so the temperature decreases over time and leads to the disposal of large amounts of asphalt concrete. This causes waste of resources and environmental pollution. Therefore, this study proposed a heat dissipation cut-off type cargo box model to solve this problem and demonstrated its performance over conventional burner-type models through tests and analysis.

An experimental investigation is performed to study the effect of jet to plate spacing and low Reynolds number on the local heat transfer distribution to normally impinging submerged circular air jet on a smooth and flat surface. A single jet from a straight circular nozzle of length to diameter ratio(l/d) of 83 is tested. Reynolds number based on nozzle exit condition is varied between 500 and 8,000 and jet to plate spacing between 0.5 and 8 nozzle diameter. The local het transfer characteristics are obtained using thermal images from infrared thermal imaging technique. It was observed that at lower Reynolds numbers, the effect of jet to plate distances covered during the study on the stagnation point Nusselt numbers is minimal. At all jet to plate distances, the stagnation point Nusselt numbers decrease monotonically with the maximum occurring at a z/d of 0.5 as opposed to the stagnation point Nusselt numbers at high Reynolds numbers which occur around a z/d of 6.

The heat transfer of Jet impingement is a very effective technique for exchanging high heat fluxs between a heated plate and a fluid. The purpose of current investigation is to carry out the experiment in order to study heat transfer characteristics between a vertical round water jet and a horizontal surface for different flow rates and geometric conditions. The effect of flow rates on heat transfer were investigated. The data obtained in this study are represented in terms of Nusselt number as a function of Reynolds and Peclet numbers. The correlation for the Nusselts number in terms of the Peclet number and  was obtained. The proposed correlation predicts the current data of heat transfer very well.