Cfd Of Double-Wedge Spiked Intake Of The Supersonic Jet Engine

Intake of the Supersonic Jet Engine requires the highest possible total pressure recovery and minimal total pressure lost in order to obtain an efficient operation. The supersonic intake is mainly affected by two substantial factors which is the geometry of the spike (double-wedge) and the angle of attack. The solution is quite direct at zero angle of attack, but at non zero angle of attack, the shock system structure will be affected and the flow distribution will be unsymmetrical in the upper (leeside) and the lower side (windward side) of the inlet. The objective of this work is to model mathematically the double-wedge spiked intake of the supersonic jet engine. The analysis will be carried out using the assumptions that the flow is viscous, steady and 2-dimensional compressible fluid flow. The whole system will be simulated and analysed numerically using CFD softwares. The available FLUENT and GAMBIT software in the department will be used for the modelling simulation. Finally this model will be used to investigate the flow characteristics at various design and operational conditions. In conclusion, the study of on the combined effect of the double-wedged spike and angle of attack is crucial as it affects the performance of the compressor, which then affects the performance of the jet engine

Effect of Grinding on Strength and Durability of GGBFS - based Concrete

This paper presents laboratory investigations on the use of ultra fine ground granulated blast furnace slag (UFGGBFS) as a mineral admixture in concrete and cement mortar cubes. Ground granulated blast furnace slag (GGBFS) is available in plenty as a waste product resulting from steel industries and posing disposal problems subsequently leading to environmental problems. GGBFS obtained in the present work was subjected to grinding for two hours using agate pestle mortar and the effect of grinding on size was monitored by testing particle size with the help of a particle size analyzer, where reduction in size was observed. The sample was later used as a partial substitute to cement. A high strength concrete mix with a characteristic compressive strength of 40 MPa was selected for the present study, and cement was replaced with UFGGBFS in three different percentages; namely 3, 5 and 7%. Compressive strength of mortar and strength and sorptivity characteristics of concrete made with UFGGBFS were studied. Test results showed that replacement of cement with 5% UFGGBFS yielded better resistance to compression and sorption in normal and aggressive environments compared to control specimens

EFFECT OF HYDRAULIC AND GEOMETRICAL PROPERTIES ON STEPPED CASCADE AERATION SYSTEM

Stepped cascade aeration system is commonly used to aerate the water and wastewater to increase the dissolved oxygen during pre and post treatment process. In the present research, experiments were conducted to evaluate the performance of a rectangular Cascade Aeration System with varying flow rates, risers and tread by maintaining constant width of the channel using water collected from reverse osmosis plant. The experiments were carried out with four different risers such as 0.15 m, 0.18 m, 0.225 m and 0.30 m. Each rise was investigated with five different tread of 0.60 m, 0.55 m, 0.50 m, 0.45 m and 0.40 m. Comprehensive experimental investigations were carried out for different hydraulic loading rates of 0.005 to 0.035 m3/s/m2. Results obtained from the experiments reveals that increasing dimensionless discharges promotes more aeration, attains a maximum up to dimensionless discharge= 2.22 and beyond this there was a significant decrease in aeration. In addition, the increased in number of steps significantly enhances air entertainment and surface fall rate in the Stepped Cascade Aeration System. A regression equation was derived by keeping aeration efficiency as response with dimensionless discharge and oxygen saturation concentration as influencing parameters. The dimension less discharge is a function of critical depth of the rectangular channel and step height, whereas oxygen saturation concentration represents the ratio of oxygen deficit and oxygen saturation concentration. Based on the experimental results, the optimum design and/or results such as number of steps (12 numbers) and hydraulic loading rate (0.025 m3/s/m2) with fixed tread width of 0.6 m were identified to achieve maximum aeration rate (0.5-0.60) in Aeration system