Theoretical Background of Mechanical Energy Conversion

Author(s):  
Ashok K. Batra ◽  
Almuatasim Alomari
Processes ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 303
Author(s):  
Lingdi Tang ◽  
Shouqi Yuan ◽  
Yue Tang ◽  
Zhijun Gao

The impulse water turbine is a promising energy conversion device that can be used as mechanical power or a micro hydro generator, and its application can effectively ease the current energy crisis. This paper aims to clarify the mechanism of liquid acting on runner blades, the hydraulic performance, and energy conversion characteristics in the runner domain of an impulse water turbine with a splitter blade by using experimental tests and numerical simulations. The runner was divided into seven areas along the flow direction, and the power variation in the runner domain was analyzed to reflect its energy conversion characteristics. The obtained results indicate that the critical area of the runner for doing the work is in the front half of the blades, while the rear area of the blades does relatively little work and even consumes the mechanical energy of the runner to produce negative work. The high energy area is concentrated in the flow passage facing the nozzle. The energy is gradually evenly distributed from the runner inlet to the runner outlet, and the negative energy caused by flow separation with high probability is gradually reduced. The clarification of the energy conversion performance is of great significance to improve the design of impulse water turbines.


2011 ◽  
Vol 317-319 ◽  
pp. 616-620 ◽  
Author(s):  
Guang Qing Wang ◽  
Zhong Wei Zhao

In this article, a novel electro-mechanical energy conversion model of power harvesting from the vibration-induced the piezoelectric stator of the traveling wave rotary ultrasonic motor was proposed. Based on the curvature basis approach, the relationship between the deduced voltage and the mechanical stain induced by piezoelectric polarization was formulated. In addition to the relationships between the maximum induced voltages at the resonance frequency, the conversion energy density and the dimensions of the piezoelectric stator were also derived. The analytical model shows that the vibration-induced voltage is proportional to the exciting electrical voltage magnitude and square of height of the piezoelectric ceramic (PZT) but is inversely proportional to the permittivity of PZT and the damping coefficient of the stator. Some simulations and experimental results demonstrate that the maximum output voltage coincides with the energy conversion analytical model.


2013 ◽  
Vol 114 (22) ◽  
pp. 224111 ◽  
Author(s):  
Ian M. McKinley ◽  
Sam Goljahi ◽  
Christopher S. Lynch ◽  
Laurent Pilon

2011 ◽  
Vol 177 ◽  
pp. 23-35 ◽  
Author(s):  
Andrzej Kot

The paper presents description of physical phenomena arising during the process of electrodynamic forming by means of axisymetric inductors generating pulse magnetic field. Presented material shows the way for determination of pressures acting on non-ferrous pipe elements with an assumption of magnetic flux variation character in system. The paper describes also stages of energy conversion from electric energy of capacitors discharge into mechanical energy of pressure forming semi-finished product. The knowledge about presented phenomena allow to predict final shape of formed product during free forming by electrodynamic method.


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