In the present work, cold flow simulation has been conducted to evaluate the frequencies and amplitudes of pressure oscillations in solid rocket motor cavity. Axisymmetric model of solid rocket combustor has been modelled and simulated using Fluent. The numerical simulations performed for laminar and turbulent calculation to observe the oscillation frequency and amplitude in combustor. The results for oscillation amplitude have been compared for laminar and turbulent flow and it was observed that a vortex produced from the shear layer has large amplitude with varying the flow rate of working cold fluid. It has been found that the vortex shedding frequency is more oscillating at initial stage and then the oscillation gradually dies out.
Learning is a continuously evolving process with a constant search for newer and more suitable strategies and tools for enhancing its effectiveness along with more student centric approaches. Heterogenous nature of the classes demands individualisation of teaching coupled with more adaptive teaching strategies. Knowledge Based Tutoring System (KBTS) is one such approach of customising instruction to the needs of individual learners. Domain Knowledge Component, Student component, Pedagogy component and Control component are used in KBTS to model different entities involved in teaching learning process.
This article reports the results of an experimental study on the freezing characteristics of PCM contained in a stainless steel spherical capsule with two and four fins of fin material of Stainless Steel with a fill volume of 90%. A suitable Phase Change Material, distilled water is used for efficient functioning of the Latent Heat Energy Storage Systems (LHTES). The effect of fins on the the solidification time has been studied at different HTF temperatures -6º C, -9º C and -12º C. The effect of sub cooling is also studied with the usage of two or four fins in the stainless steel capsule. The experimental results indicated that there was a considerable reduction in the solidification time ranging from 3% to 33.3% with the help of two extended surfaces at different HTF temperatures -6º C, -9º C and -12º C. But with the four fins in the metallic capsule, the solidification time increased at various HTF temperatures. In case of four SS fins spherical encapsulation the solidification time increased in the range from 8% to 14.5%.
Women constitute around half of the aggregate total populace. So is in India moreover. They are, in this way viewed as the better 50% of the general public. In traditional societies, they were bound to the four dividers of houses performing family exercises. In present day societies they have left the four dividers to take part in a wide range of exercises. The worldwide evidence shows that women have been exceedingly performing well in various circles of exercises like governmental issues, political issues, administration, social work etc. Presently, have begun diving into industry additionally and running their endeavors effectively. In this way, the academic researchers at present talking about on entrepreneurial improvement, if appears in the wellness on the setting to learn about the advancement of women entrepreneurs in the nation. These induce the researcher to do this research
The energy transfer during the friction clutch operation is followed by dissipative process through convection at friction surface. To improve the performance of the friction clutch, it is important to analyze maximum temperature rise at the friction surface different design variants of grooves on the clutch plate were analyzed using CFD and FEA techniques to determine the optimum design which has good air flow around grooves and bears considerable amount of load which is imposed at the time of engagement. According to the results, a new clutch plate design is suggested, which has tapered groove geometry. The results shows improvement of the convection between air and friction surface in new design, resulting in reduced maximum temperature rise . The software ANSYS 18 and Starccm+ 12.0 are used for the numerical computation and analysis in this paper.
The concept of FSW given by TWI of UK, has now become a substitute of earlier welding methods for many alloys which are considered difficult to weld. Commercially accessible plates of AA2024-T3 having 150×75×6mm dimensions are taken for carrying out Friction Stir Welding (FSW) to fashion joints on which DOE was smeared to mainly conclude the vital dynamics having detrimental effect on features like hardness, Ultimate Tensile Strength (UTS) of such joints etc. Here, firstly Taguchi method using L9 orthogonal array is utilized for investigating impact of three chosen factors i.e. TA (tool tilt angle), TRS (Tool rotational speed) and TS (traverse speed) on hardness, UTS as well as for sensing optimally process parameters of such welding joints. Secondly, ANOVA analysis is done for determining the “percentage contribution” of each factor on UTS as well as Hardness.
The requirement of dissimilar metal welding is the most focused technology for the present-industrial applications likes nuclear power plants, aerospace components, and etc. Welding of different aluminium grades has spread the extent of applications into lightweight, non-corrosive and strength to weight ratio products. As the weld joint should have adequate strength for efficient use proper method, design and parameters section is mandatory. Friction Stir welding for welding, Taguchi for experimental design and Grey relation Analysis for parameter optimization are carried out in this investigation multi-response optimization of welding characteristics to join AA6061-T6 to AA7075-T6 aluminium alloys. To weld quality the responses such as ductility, hardness and tensile strength are optimized for process parameters are tool rotation ,welding speed and tool geometry. The derived optimal welding conditions are taper hexagonal pin profile,The tool rotation speed of 1200 rpm, and welding speed of 12 mm/min.
Polypropylene/styrene-butadiene-styrene (SBS) silica nanocomposites were mixed in a twin screw Brabender Plasticorder, the weight percent of the SBS was varied at (0, 5, 10, 20 and 40), and the silica content was varied at (0, 0.05, 0.1, 0.5, 1 and 2) wt%. The mechanical properties of these nanocomposites were studied using a Tensile Testing and Impact Testing machines. It was observed that increasing the SBS content lead to a drastic improvement in the impact strength, with over a 6-fold increase at maximum. Young’s modulus decreased with increasing SBS content, with the highest decrease being approximately 35% at PP/SBS ratios of 60/40, excluding samples having this composition caused the highest decrease to drop to 25%. A proportional correlation was observed between the elongation at break and SBS content; on the other hand, an inversely proportional one was noticed between the yield stress and SBS content.
This paper presents the design, fabrication and testing of a smart metering device for Heating, Ventilation and Air-Conditioning (HVAC) systems. The device was fabricated by using Arduino UNO shields combined with GSM module (SIM900A) and current sensor or current transformer (CT). The device was used to measure the power consumption of the air-conditioner. It was observed that the device can read and calculate the current flow directly from current transformer (CT). From the CT, the value of power consumption could be measured and the Arduino programming would run the calculation of the parameters and display the values on the LCD. The device was tested on the computer linked Air Conditioning laboratory unit in thermofluids lab. It can be concluded that the device can help to improvise monitoring system on air-conditioning power consumption. The device can be a handful gadget for all users to estimate their power consumption independently.
A water cooling system based on Peltier Effect has many benefits as being small in size, portable, noiseless, environmental friendly and economical compared to conventional cooling systems. This research focuses on the thermal performance experimental study of a portable thermoelectric water cooling system. During this study, the applied voltage on TE was changed to determine its effect on thermal performance. When the applied voltage increases, the hot side temperature incresing, while on the contrary of that appear on the cold side. This increasing the heat absorbed by the cold side as well as the heat rejected from the hot side, while the coefficient of performance decreasing with increasing applied voltage. The thermal resistance of heat sink is inversely proportional to the applied voltage. The increasing of heat sink fan speed has improved the system performance, where it leds to an increasing in heat absorbed by the cold side and the heat rejected from the hot side. Initial water temperature has a significant effect on the performance of TE water cooling system. The coefficient of performance equal to 0.14 when using initial water temperature of 15℃, while, it increase to be 0.5 when the initial water temperature increases to 30 ℃. That is happened due to the decrease in temperature gradient between cold side and hot side.