scholarly journals Simulation of Piezoelectric Stack Actuators for Loss Component

2021 ◽  
Vol 14 (4) ◽  
pp. 153-160
Author(s):  
Mark Christian P. Espinosa ◽  
Paola N. Calub ◽  
Rodney B Javier ◽  
Sheryl Dinglasan Fenol
Keyword(s):  
2020 ◽  
Vol 142 (11) ◽  
Author(s):  
Michael J. Hurrell ◽  
Jerzy T. Sawicki

Abstract High speed rotorcraft transmissions are subject to load-independent power losses consisting of drag loss and pumping loss. Tightly conforming shrouds enclosing the transmission gears are often incorporated to reduce the drag component of the total load-independent losses. However, tightly conforming axial shrouds can result in an increase in the pumping loss component. Quantifying the pumping loss of shrouded gear transmissions has been the subject of many studies. This study presents a new approach for estimating pumping loss based on the concept of swept volume and examines the applicability of the approach to various shroud configurations. The drag loss and pumping loss of a shrouded spur gear pair have been determined through testing using the NASA Glenn Research Center (GRC) Gear Windage Test Facility. The results from this testing have been compared to theoretical results using the formulations presented in this study. In addition, computational fluid dynamics (CFD) analysis has been conducted for the various shroud configurations tested at NASA GRC. The results from the CFD analysis confirm the theoretical and empirical results and provide insight into the applicability of the swept volume approach for estimating pumping power loss of shrouded gear transmissions.


1988 ◽  
Vol 108 ◽  
pp. 102-113
Author(s):  
Cornelis de Jager ◽  
Hans Nieuwenhuijzen

AbstractA review is given of rate of mass-loss values in the upper part of the Hertzsprung-Russell diagram. Near the luminosity limit of stellar existance = −10−4 M⊙ yr−1. Episodical mass loss in bright variable super- and hypergiants does not significantly increase this value. For Wolf-Rayet stars the rate of mass loss is larger by a factor 140 than for non-evolved stars with the same Teff and L; for C stars this factor is ten. This can be explained qualitatively. Rotation appears hardly to influence the rate of mass loss except for vrot-values close to the break-up velocity. This is in accordance with theory. We suggest the existence of a Red Supergiant Branch; along that branch mass loss is virtually independent of luminosity. Stellar winds along the upper limit of stellar existence are mainly due: to radiation pressure for hot supergiants (≳ 10 000 K); to turbulent pressure for cool supergiants (3000-10 000 K), and to dust-driven and pulsation-driven winds for cooler stars. The turbulent pressure may originate in largescale stochastic motions as observed in Alpha Cyg. Episodical mass loss, as observed in P Cyg, HR 8752 and other Very Luminous Variables may be due to occasional violent stochastic motions, resulting in a shock-driven episodical mass-loss component.


Author(s):  
M. K. Sinha ◽  
N. N. Thombare ◽  
B. Mondal ◽  
M. S. Meena ◽  
Pankaj Kumar

Response from 60-farm owners was analyzed to assess the economic impacts of foot and mouth disease. Data were recorded through personal interview methods during 2006-07 from small farmers across the villages of Pune region. The loss in terms of reduced revenues and cost as extra resources used for treatment were quantified and aggregated. The estimated production loss to the tune of Rs. 3184.00 in crossbreeds cows and Rs. 3062.50 in buffaloes, whose share was 74.31 and 81.69 per cent, respectively. The major loss component was reduction in milk yield, accounted Rs. 894.60 and Rs.510.00, represents 20.88 and 13.60 per cent of the total loss in crossbred cows and buffaloes, respectively. The cost of treatment was worked out to be Rs. 1313.80 in crossbred cows and Rs. 645.63 in buffaloes. The cost of medicine alone had constituted around 50 percent of total cost component, reflecting a tune of Rs. 675.60 in crossbred and Rs. 281.25 in buffaloes. The expenses were worked out to be Rs. 5598.80 in crossbred and Rs. 4394.38 in buffaloes per animal, which shows the expenses due to the disease, was comparatively higher in the crossbred cows. Movement of animals was ascertained to be the reason for spread of this disease in 80 per cent farm perception.


1985 ◽  
Vol 459 (1 Hematopoietic) ◽  
pp. 367-374 ◽  
Author(s):  
N. RAPHAEL SHULMAN ◽  
JAMES V. JORDAN ◽  
STEVEN FALCHUK

2020 ◽  
Vol 8 (6) ◽  
pp. 4011-4016

This article planned the power investment strategies that coordinates the power distribution line loss component with the distribution factors. Improved power investment strategies technique for the entire power market. The online price estimator analyzes transfer breaks down exchange rates dependent on specific instruments at the advancement cost list , which work vigorously to modify offers and agreement the executives, which implies that online vitality exchanging expenditure a ton of cash. The planned approach was tried on the IEEE30 bus test arrangement utilizing MATLAB documents from the MATPOWER reproduction program to break down the vitality stream and perfect vitality stream issues. It is a reenactment device that permits reviews and educators to be handily utilized and adjusted to exhibit the various outcomes between valuing plans. The diverse value parameters are a fundamental game plan in the test arrangement, which is associated with overburdening, steering, and promote the techno-financial examination of the exchanging theory with the foundation computations completed. accessible online as an extra establishment


Author(s):  
Michael J. Hurrell ◽  
Jerzy T. Sawicki

Abstract High speed rotorcraft transmissions are subject to load-independent power losses consisting of drag loss and pumping loss. Tightly conforming shrouds enclosing the transmission gears are often incorporated to reduce the drag component of the total load-independent losses. However, tightly conforming axial shrouds can result in an increase in the pumping loss component. Quantifying the pumping loss of shrouded gear transmissions has been the subject of many studies. This study presents a new approach for estimating pumping loss based on the concept of swept volume and examines the applicability of the approach to various shroud configurations. The drag loss and pumping loss of a shrouded spur gear pair has been determined through testing using the NASA Glenn Research Center (GRC) Gear Windage Test Facility. The results from this testing have been compared to theoretical results using the formulations presented in this study. In addition, computational fluid dynamic (CFD) analysis has been conducted for the various shroud configurations tested at NASA GRC. The results from the CFD analysis confirm the theoretical and empirical results and provide insight into the applicability of the swept volume approach for estimating pumping power loss of shrouded gear transmissions.


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