Purna Chandra Mishra

A brief review on viscosity of nanofluids

Since the past decade, rapid development in nanotechnology has produced several aspects for the scientists and technologists to look into. Nanofluid is one of the incredible outcomes of such advancement. Nanofluids (colloidal suspensions of metallic and nonmetallic nanoparticles in conventional base fluids) are best known for their remarkable change to enhanced heat transfer abilities. Earlier research work has already acutely focused on thermal conductivity of nanofluids. However, viscosity is another important property that needs the same attention due to its very crucial impact on heat transfer. Therefore, viscosity of nanofluids should be thoroughly investigated before use for practical heat transfer applications. In this contribution, a brief review on theoretical models is presented precisely. Furthermore, the effects of nanoparticles’ shape and size, temperature, volume concentration, pH, etc. are organized together and reviewed.

Tool wear in turning ceramic reinforced aluminum matrix composites—A review:

Cutting tool wear during turning of ceramic reinforced aluminum matrix composites was reviewed. Though tools of different materials, such as tungsten carbide, coated tungsten carbide, ceramics, cubic boron nitride, polycrystalline cubic boron nitride, chemical vapor deposition diamond coated tungsten carbide, and polycrystalline diamond were used for turning the aluminum matrix composites, better performance of polycrystalline diamond tools was observed in terms of tool life. The results obtained by many researchers indicated that dominant tool wear mechanism was abrasion, and tool life was mainly affected by flank wear during turning of these composites. The flank wear increased on increasing particulate size or weight fraction of reinforcement. Flank wear of the cutting tool also increased with increasing cutting speed, feed, and depth of cut; however, cutting speed was the most significant parameter affecting flank wear, followed by feed. Influence of depth of cut on flank wear was limited or insignificant.

Performance assessment in hard turning of AISI 1015 steel under spray impingement cooling and dry environment

This work investigates the effects of cutting parameters on surface roughness (Ra, µm), cutting temperature (T, °C) at the chip–tool interface and the material removal rate during hard machining of AISI 1015 (43 ± 1 HRC) steel using carbide insert under dry and spray impingement cooling environment. A combined technique using orthogonal array and analysis of variance was employed to investigate the contribution of spindle speed, feed rate, depth of cut and air pressure on responses. It is observed that with spray impingement cooling, cutting performance improves compared to dry cutting. The predicted multi-response optimization setting (N3-f1-d1-P2) ensures minimization of surface roughness, cutting temperature and maximization of material removal rate.

Performance and Emission Analysis of a Novel Porous Radiant Burner for Domestic Cooking Application

ABSTRACT Present study focuses on the performance and emission analysis of a novel porous radiant burner for domestic cooking application using liquefied petroleum gas (LPG) as fuel. The porous radiant burner (PRB) used here is a novel ceramic porous radiant burner which is designed and developed in the University laboratory for this present study. Two kinds of PRBs as circular porous radiant burner and square porous radiant burner have been developed and hence the thermal efficiency and emission analysis of these burners are tested for their performance. The test results are very encouraging as the thermal efficiency of the circular porous radiant burner and square porous radiant burner are much higher as compared to the conventional metallic burners or other types of burners. The emission characteristic also shows that the emission of CO and NOx values are much lesser than the conventional burner and are well within the world health organization standard. The experimental setup used here is a flexible one that contains PRBs, LPG cylinder, K- type thermocouple, data acquisition system, flue gas analyzer, Infrared camera and a computer. The maximum thermal efficiency obtained in that test for the PRB is about 72% which indicates its bright future prospect.

Effect of Impingement Density and Nozzle to Target Distance on Spray Cooling of Steel Plate—An Experimental Investigation

ABSTRACT In the steel making industry, high heat fluxes are obtained using effective cooling techniques such as spray impingement cooling. Spray impingement technique involve factors like droplet size, spray height and spray angle, impingement density, and nozzle geometry rendering it very difficult to measure the effects of individual parameters. In the present study, the cooling rate of the plate was experimentally investigated using distilled water as coolant in 3 pressurized nozzles for spray over the surface of the steel plate at elevated temperatures and the behavior of plate temperature with time was tabulated. Cooling curves were generated for different and varying spray parameters like water pressures, nozzle tip to surface distance, and impingement density. It was observed that the cooling rate at the stagnation zone was strongly dependent on the water pressures and nozzle tip to surface distances with maximum cooling rates reaching within 1–2 seconds after the impingement. The average impingement density increased with increase in water pressure and the cooling rate reduces at higher pressures and nozzle tip to surface distances.

Application of neem biodiesel and dimethyl carbonate as alternative fuels

ABSTRACT The present study focuses on the application of neem biodiesel and dimethyl carbonate as alternative fuels for modern engines, examining their properties and emission characteristics under varying load conditions. Experimental results show improved emission characteristics at an optimum load of 80%. There was a decrease in both hydrocarbons and carbon monoxide and an increase in additive blends with biodiesel. Similarly, smoke opacity was higher for pure biodiesel but fell with an increase in the percentage of additives. Therefore, the present article highlights the utilization of biodiesel in modern vehicles using various fuel additives under different operating conditions.

Enhancement of heat transfer by water–Al2O3 and water–TiO2 nanofluids jet impingement in cooling hot steel surface

ABSTRACT Two different nanofluids, namely water–Al2O3 and water–TiO2, were impinged in the form of jet on hot steel surface to remove high heat flux, and their performance was compared. The dimension of the test steel sample was 120 mm × 120 mm and 4 mm thickness. Four K-type thermocouples were embedded on the bottom surface of the plate to measure the transient temperature distribution. The time-temperature data were recorded by the help of a data acquisition system (make: CHINO, model: KR2000), and the results were analysed by ZAILA application software. Effect of impinging nanofluids with weight concentrations of 0.01%, 0.03%, 0.05% and 0.07% Al2O3 and TiO2 nanoparticles on heat transfer from the hot surface was tested. The surface heat transfer coefficient (HTC) was computed from the time-temperature history recorded during experimentation. Experimental results revealed that addition of nanoparticles to the base fluid (water) surprisingly enhanced the heat transfer rate and HTC as expected. The heat transfer rate increased up to certain limit of nanoparticle concentrations, and then declined. Application of nanofluids for the steel strip cooling was found very effective in terms of heat transfer phenomena as compared to the conventional fluid cooling methods.

Comparative Performance In Hard Turning Of AISI 1015 Steel With Carbide Insert Using Orthogonal Array Design And Grey Relational Analysis Under Spray Impingement Cooling And Dry Environment: A Case Study

This study investigates the effects of cutting parameters on surface roughness (Ra), cutting temperature (T0C) at the chip tool interface and the material removal rate (MRR mm3/min) during hard machining of AISI 1015 (43 HRC) steel using carbide insert under dry and spray impingement cooling environment. A combined technique using orthogonal array and analysis of variance (ANOVA) was employed to investigate the contribution of spindle speed, feed rate, depth of cut and air pressure on responses. Utilization of IR camera is been effective to calculate the temperature at the interface of workpiece and the tool. It is observed that with spray impingement cooling, cutting performance improves compared to dry cutting. The predicted multi response optimization setting (N3-f1-d1-P2) ensures minimization of surface roughness, cutting temperature and maximization of material removal rate. Finally optimal result was validated by confirmatory test and the improvement in grey relational grade was found to be 0.288.

Response surface method-based optimisation of spray parameters during impingement cooling of hot steel in rolling

Response surface methodology was employed for optimising the complex air-water spray mechanisms that occur in hot surface cooling processes where forced convection exists. Results from a physical air-water spray cooling experiment were generated and the experimental parameters were optimised for achieving heat flux from the surface of a hot steel test plate of dimension 120 mm × 120 mm. The thickness of the plate was considered as one of the variable (4 mm, 6 mm and 8 mm) during the experimentation. The other variables in the problem were the nozzle to plate distance, air pressure and water pressure. The experiments were carried out based on the response surface design of experiments. The heat flux was calculated by using Newtons convection model. The optimisation of the controlling parameters was carried out by using the response surface method (RSM). A new mathematical correlation was developed for optimisation of the surface heat flux.

Theoretical modeling and optimization of microchannel heat sink cooling with TiO2-water and ZnO-water nanofluids

Received: 28 November 2017 Accepted: 2 February 2018 This investigation intends to present a theoretical analysis, comparison and thermal optimization of a rectangular microchannel heat sink cooling by TiO2-water and ZnOWater nanofluids. Nanofluids at volume fractions of 1%, 2%, 4%, 6%, 8% and 10% are applied to evaluate and enhance the performance of the microchannel heat sinks. Engineering Equation Solver (EES) is used for optimizing the performance of heat sink. The inclusion of nanoparticles in the base fluid consequences to the reduction in thermal resistance with concurrent growth inthe pumping power. The reduction is thermal resistance is more intense for ZnO-water nanofluids than TiO2-water nanofluids (0.0000170 KmW with TiO2-water and 0.0000136 KmWwith ZnO-water at 8%volume fraction). However, the pumping power needed for both the nanofluids at different volume fractions are found to be same (0.53W for both fluids at 8% volume fraction). The diminution of thermal resistance at same pumping power makes ZnO-water nanofluids a potential candidate than TiO2-water nanofluids. Heat sink made with material of high thermal conductivity showed superior cooling performance. Additionally, for identical operative condition, both the nanofluids achieve quicker cooling performance than water. Consequently, nanofluids should be regarded as the future of the cooling agents for electronic cooling embarking excellence in the field of thermal optimization technology.