Thermal Heat Transfer Essay

Thermal properties of liquids play a major role in thermal related applications in industrial processes. The heat transfer property of any fluid is dependent mainly on its thermal conductivity. Conventional heat transfer fluids have poor thermal conductivity which makes them inadequate for high thermal applications. Scientists have tried to enhance the inherently poor thermal conductivity of such conventional heat transfer fluids using solid additives. Fine tuning of the dimensions of these solid suspensions in millimeter and micrometer ranges for getting better heat transfer performance have failed because of the drawbacks such as still low thermal conductivity, particle sedimentation, corrosion of components of machines, particle clogging, excessive pressure drops etc. Downscaling of particle sizes continued in the search for new types of fluid suspensions having enhanced thermal properties as well as heat transfer performance.

All physical mechanisms have a critical scale below which the properties of a material changes totally. Modern nanotechnology offers physical and chemical routes to prepare nanometer sized particles or nanostructured materials engineered on the atomic or molecular scales with enhanced thermo-physical properties compared to their respective bulk forms.

In heat transfer mechanism thermal conductivity of fluid plays a vital role. So we require fluid with higher thermal conductivity to get high heat transfer. Experimental result shows that solid metal particle has high thermal conductivity. Utilize that small (1<100 nm in diameter exhibit properties different from those of conventional solids. Compared with micron-sized particles, nanophase powders have much larger relative surface areas and a great potential for heat transfer enhancement. Some researchers tried to suspend nanoparticles into fluids to form high effective heat transfer