Solar air heater is the cheapest and extensively used solar energy collection device for drying of agricultural products, space heating, seasoning of timber and curing of industrial products. The use of an artificial roughness on a surface is an effective technique to enhance the rate of heat transfer to fluid flow in the duct of a solar air heater. In this study to investigate the relative performance of different types of artificially roughened solar air heater. The objective of this article is toper form such a study. In this article two known different shapes and orientations of roughness elements are considered for comparative analysis. Correlations for heat transfer and friction factor, developed by various investigators for artificially roughened solar air heaters have been reported in this article. The effects of various rib parameter son heat transfer and fluid flow processes are also discussed.

Fossil fuel is the main source for the production of energy used today. Due to the continuous rise in the cost of fossil fuel and demand of pollution free environment and clean energy is increasing. Alternative fuel has become very noticeable and has a relevant role to play for both CI & SI engines, so it is important to reduce down dependency of gasoline as a fuel. Many research and investigation have been done focusing on using alternative fuel and minimizing the effect on fuel utilization and growing engineperformance. It is known that future availability of energy resources as well as reducing carbon dioxide from fuel has increased the need of other way to replace the fuels. This investigation is done by taking commercial petrol as reference which is blended with 10%, 15% and 20% of methanol blend with petrol. Physical properties of fuel were determined for these three blends of gasoline. A three cylinder, four stroke, varying rpm, petrol MPFI engine was tested on blends contains 10%, 15%, and 20% methanol. The performance characteristics and exhaust temperature were measured. The result shows there is reduction in petrol consumption and also increase in Brake Power, Brake Thermal Efficiency, volumetric efficiency, on blending. So, we can finish from result that 15% methanol blend is mainly effective and we can use it in further use in SI engine with little constrains on material used to continue little boost in pressure without any engine modification.