This should give a clear picture of how small a nanometer is. Particles of a few to or hundreds of nanometers in terms of diameter have some distinctive physiochemical and surface properties and that allows them to offer themselves to innovative uses like water treatment, medicine, energy, agriculture and many more. Water purification using nanotechnology is a very complex
CHAPTER-2 NANO FLUIDS Nano fluids are a new kind of approach for heat transfer applications. Nano fluids are containing nanoparticles having size of 1–100 nm, which are uniformly and stably suspended in a base fluid. Generally metals or metal-oxides used as Nanoparticles and they greatly enhance the thermal conductivity of the Nano fluids. Nano fluids have been considered for so many industrial applications for advanced heat transfer fluids for two decades. However, due to complexity of the Nano fluid systems, there is no agreement has been achieved in heat transfer processes.
The technology of enhanced heat transfer has received strong attention over the last 3 to 5 decades . Interesting characteristics of heat transfer when compared to the traditional fluids of heat transfer are the outcomes of these modern concepts of nanofluids. Lots of research work has been carried out in recent years on superior properties of the nanofluids for heat transfer particularly their convective heat transfer rates and their thermal conductivities . Owing to these features of nanofluids, they have wide range of promising industrial applications such as in devices which exchanges the heat. Also this technique of heat transfer enhancement by means of nanofluids is equally applicable to application areas like electronics devices, bulky automobiles, power generation plants, refrigeration and air-conditioning systems, process industries, nuclear sectors and chemical industries and so on.
This process takes place in a conical or cylindrical cyclone, solutions of drug Nano suspensions produced by HPH are sprayed feed from the up to down, even hot air is applied from the same direction and spherical shape particles are obtained. Polymers, sugars or sugar alcohols like mannitol or sorbitol are water soluble matrix which are used for drug Nano suspension formulation. Atomizer is used for spraying which rotates rapidly and due to the centrifugal effect scattering to the solution takes place. Nitrogen gas or air at constant pressure are applied via outer tube. Spraying can be done by nozzle which leads to very small particles i.e.
Because nanotechnology is essentially a set of techniques that allow manipulation of properties at a very small scale, it can have many applications in all parts of life. Nanotechnology is viewed broadly as many technologies over time are expected to generate numerous new products and applications. Lux Research, Inc., the New York-based nanotechnology research and advocacy firm, predicts that by 2015 products that incorporate nanotechnology will constitute 15 percent of global manufacturing output and will total $3 trillion. Products of nanotechnology are diverse and growing exponentially. According to the NNI, nanoparticles and nanoscale materials are used in many industries, including electronics, pharmaceuticals, chemicals, energy, and biomedical, among others.
Improving the thermal efficiency of the engine leads to decrease in concentration of emissions in the exhaust. Nanoparticles improve the cooling rate when they are used along with coolant oil as base fluid in cooling systems. The rising demand for powerful and efficient engines call for the use of a coolant with better heat transfer characteristics. KEYWORDS: Nanofluids, Automobile radiator, Heat transfer Enhancement, Thermal conductivity.
They analyse variations of exergy transfer effectiveness with number of transfer units (NTU), with the ratio of the heat capacity of cold fluid to that of hot fluid (Cc/Ch) and with finite pressure drops. They note that there is not an optimal combination of NTU and Cc/Ch for maximising exergy transfer effectiveness. They donot elaborate on the effects of temperature variations.Johannessen et al. (2002) examine temperature profiles and local entropy productionprofiles in heat exchangers. They show that the standard counter-current heat exchanger is the best first approximation to optimal heat exchange conditions in practice, as it has, mqualitatively the same properties as the optimal solutions presented in their study; when the temperature difference Th – Tc between the hot and the cold fluids is approximately constant.
Recently, in their second and third papers (Naphon and Wongwises [14,15], mathematical models to determine the performance and heat transfer characteristics of spirally coiled finned tube heat exchangers under wet-surface conditions and dry-surface conditions were developed Analysis of Heat Transfer by Cascading Spiral Inner Tube in a Heat Exchanger 10 and investigated. There was reasonable agreement between the results obtained from the experiment and those from the developed model. As mentioned above, only a few works on the heat transfer characteristics in spiral coil heat exchangers have been reported. The literature survey revealed that though many researchers have investigated the use of different geometries on plate surface to enhance heat transfer, there is still a dearth of work to explain what type of geometry provides best heat transfer enhancement for a specific thermal boundary condition. And also some of the literatures were unable to make any conclusions about friction factor for such type of problems.
INTRODUCTION With the rapid progress of technology and science, nanotechnology becomes a prominent accomplishment of the humanity. The ability to observe and comprehend the nanomaterial has a beneficial human to extend our knowledge in a variety range of industries and scientific endeavors. Nanotechnology is defined as a structure that conducted the size of one nanometer to one hundred nanometers and it is invisible to the human eye. Nanotechnology allows the scientists to manipulate one particular particles property at a very small size and adapt it in any applications in real life (Understanding Nano, 2016). One of the applications that makes nanotechnology exceedingly successful is the use of nanomaterial in sunscreen Sunscreen provides