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Effect of Groove Location on Pressure Profile of Twin Axial Groove Journal Bearing

2020-12-01T00:00:00Z

Title: Effect of Groove Location on Pressure Profile of Twin Axial Groove Journal Bearing Authors: Dwivedi, Vijay Kumar; Pathak, Pooja; Sharma, Kamal; Saraswat, Manish Abstract: The main aim of current work is to analyze the influence of groove location on the pressure profile of the hybrid journal bearing. The objective is to develop solution algorithm and computer program which will provide pressure profile developed in the space of clearance of bearing having a given value of Somerfield number. The solution algorithm shall also provide three dimensional pressure profiles of the bearing for different groove location. It was found that groove location with respect to the loading line strongly influences the parameters of performance because of the stronger groove interference in the pressurized hydrodynamic field. The comparison of circumferential pressure with angular location from +X-axis is shown for the ratio of length to diameter which comes out to be 0.5, the clearance ratio (C/R) is found to be 0.00294 while 1125 rpm is the speed. The groove axes optimal location lies between 60° to 90° (∝₁ g =0°) to the line of loading. Page(s): 1049-1052

CFD-Based Analysis of Wedges Water Entry under Impact Loads

2020-12-01T00:00:00Z

Title: CFD-Based Analysis of Wedges Water Entry under Impact Loads Authors: Lyu, Xujian; Tang, Dongdong; Guan, Yanmin; Sun, Jianglong Abstract: The impact on a falling wedge upon water entry is numerically investigated in this paper. After verified by experimental data, the numerical framework is applied for parametric studies on wedges of different drop heights and different deadrise angles to reveal the interaction behaviour between the wedge and water during impact. Pressure distribution on the wedge surface during the water entry shows that the pressure peak moves up along the surface as impact time increases. It is found that the force peak decrease with the increase of drop height and decrease of deadrise angle of the wedge. The peak positions move positively along the timeline as the increase of deadrise angle while the peak force appears just in a small impact time range for a wedge. Page(s): 1053-1056

Design and Development of a Digital Controlled Dielectric Barrier Discharge (DBD) AC Power Supply for Ozone Generation

2020-12-01T00:00:00Z

Title: Design and Development of a Digital Controlled Dielectric Barrier Discharge (DBD) AC Power Supply for Ozone Generation Authors: Krishna, T N V; Himasree, P; Rao, S Srinivasa; Kumar, Yedluri Anil; Kundakarla, Naga Bhushanam; Kim, Hee-Je Abstract: A digital controlled dielectric barrier discharge (DBD) AC (Alternative current) power supply is designed and investigated. The power source design with a diode bridge rectifier and PWM (Pulse Width Modulation) inverter along with driver circuits are presented. A step-up transformer is designed to carry 4.6 kW and 10 kVp-p for a dielectric barrier discharge (DBD) AC power supply and ozone generation. An STM (STMicroelectronics) microcontroller is employed to control the phase shift angle of the PWM inverter. The operating frequency of the PWM inverter is 25 kHz. Zero voltage detection can be reached and achieves maximum efficiency. Also, a high voltage transformer is included. The practical results shown that the DBD power supply can be controlled at the chosen value and extreme efficiency can be 87.45 % at 4.6 kW/10 kVp-p. Page(s): 1057-1068

An Efficient Source Localization Method in Presence of Multipath using Smart Antenna System

2020-12-01T00:00:00Z

Title: An Efficient Source Localization Method in Presence of Multipath using Smart Antenna System Authors: Ganguly, Saurav; Ghosh, Jayanta; Kumar, Puli Kishore; Mukhopadhyay, Mainak Abstract: In this paper, a MATLAB based smart antenna testbed that efficiently localizes the line-of-sight (LOS) source in the presence of multipath signals is developed. By exploiting the consistent amplitude nature of the LOS signal, a variant of Constant Modulus Algorithm, namely Multitarget-Least Square Constant Modulus Algorithm is employed to adapt and update the weights of the smart antenna for estimation of the direction-of-arrival (DOA) of the of the LOS and multipath interference signals. Performance is compared with the conventional and recently proposed algorithms in the same testbed with alike considerations. Simulation result shows that the proposed method of DOA estimation performs better in terms of probability of resolution and root mean square error. Page(s): 1069-1073