Multi-Disciplinary Optimization of Mid-Span Shroud Ring Structure: A Multi-Parameter Geometry Study Case

2012 ◽  
Author(s):  
Yuan-Ting Wu ◽  
Jerome Le Moine ◽  
Pei-feng Hsu ◽  
Christian K. Funk ◽  
C. Subramanian ◽  
...  
Keyword(s):  
Drag Force ◽  
High Efficiency ◽  
Turbine Blades ◽  
Ring Structure ◽  
Computational Time ◽  
Negative Effects ◽  
Geometry Model ◽  
Study Case ◽  
Two Parameter ◽  
High Output

In modern industrial high-output, high-efficiency engines, long turbine blades can require the use of a mid-span or partial-span damping ring for damping vibrations. However, the inclusion of a mid-span damping shroud, or “snubber,” can have negative effects on the aerodynamic performance of the gas turbine stage and engine. Therefore, a method of coupling two independent computational fluid dynamics and finite element structure software tools under an optimization environment was applied to minimize the drag force caused by the snubber, while maximizing the structural life of the blade. Following the earlier two-parameter (the shroud width and taper ratio) shroud geometry study by the authors, this study extends to the five-parameter geometry model to approach a higher performance design with controllable computational time as well. For the optimized turbine blade shroud in this case, 14.5% reduction of the maximum material stress and 22.6% decrease in the drag force from original snubber design has been accomplished.

Design Optimization of Turbo-Machinery Components With Independent FEA and CFD Tools in an Optimization Software Environment: A Mid-Span Shroud Ring Study Case

2011 ◽  
Author(s):  
Yuan-Ting Wu ◽  
Christian K. Funk ◽  
Pei-feng Hsu ◽  
Jerome Le Moine ◽  
Ran Zhou ◽  
...  
Keyword(s):  
Gas Turbine ◽  
Drag Force ◽  
High Efficiency ◽  
Aerodynamic Drag ◽  
Low Cycle Fatigue ◽  
Turbine Blades ◽  
Integrated Design ◽  
Software Environment ◽  
Optimization Software ◽  
Parametric Studies

Shrouds are important for damping vibrations in gas turbine blades. In modern industrial high-output, high-efficiency engines, long turbine blades can require the use of a mid-span or partial-span damping ring. However, the inclusion of a mid-span damping shroud, or “snubber,” can have negative effects on the aerodynamic performance of the gas turbine stage and engine. Therefore, a method of iterative study and optimization was applied to minimize the drag force caused by the snubber, while maximizing the structural life of the blade. The approach used integrated design environment software to perform parametric studies of the design space in preparation for optimization of the blade snubber geometry. The drivers employed in Isight 4.0/4.5 [9] optimization software carried out the parametric study and reported the results to the designer. Considering these results, the designer chose the initial seeding geometry of the optimization driver which greatly reduced analysis time and the time required to reach the design objectives. This approach provides an integrated design workflow and facilitates parametric studies of advanced gas turbine blade component geometry, and the optimization of the component to meet targets of minimized aerodynamic drag force and maximized low-cycle fatigue life, goals crucial to the development of an advanced and efficient power generation gas turbine.

Inspector Quadro - the complex of preparation for the treatment of ectoand endoparasitoses in cats and dogs

2018 ◽  
Vol 12 (2) ◽  
pp. 75-84
Author(s):  
M.V. Arisov ◽  
I.P. Belykh ◽  
V.V. Artemov
Keyword(s):  
Body Weight ◽  
Clinical Picture ◽  
High Efficiency ◽  
The Body ◽  
Negative Effects ◽  
Laboratory Methods ◽  
Diagnosis Of Infection

The purpose of the research: the study of the efficacy of the preparations for veterinary use "Inspector Quadro C" and "Inspector Quadro K" against ecto- and endoparasitoses of dogs and cats. Materials and methods. Studies were conducted on spontaneously infected dogs and cats of different sexes, age, weight and breed. The diagnosis of infection with ectoparasites was made based on the clinical picture and laboratory methods of investigation (microscopy of scrapings taken from ectoparasitized skin areas, examination of the coat for fleas, lice, worms, ixodids). Infection with helminths was established by detecting eggs of helminths in faeces of animals by the method of Füleleborn and mature segments of cestodes. Preparations were applied to the animals by drip application on dry undamaged skin in places inaccessible to licking in a dose of 0.1-0.4 ml per 1 kg of body weight. The results were statistically processed. Results and discussion. "Inspector Quadro S" and "Inspector Quadro K" showed 100% efficacy at sarcoptosis in dogs, notoedrosis in cats, otodectosis in dogs and cats, ixodidoses and entomoses. "Inspector Quadro C" showed a high efficiency (92.3%) at demodecosis in dogs. However, single mites were found in one dog. 100% efficacy of "Inspector Quadro C" and "Inspector Quadro K" has been established against intestinal nematodes and cestodes in dogs and cats. Negative effects of drugs on the body of animals have not been revealed.

scholarly journals Novel semi-analytical optoelectronic modeling based on homogenization theory for realistic plasmonic polymer solar cells

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Zahra Arefinia ◽  
Dip Prakash Samajdar
Keyword(s):  
Solar Cells ◽  
Active Layer ◽  
Analytical Modeling ◽  
High Efficiency ◽  
Polymer Solar Cells ◽  
Scattered Light ◽  
Homogenization Theory ◽  
Computational Time ◽  
Coupled Equations ◽  
Long Time

AbstractNumerical-based simulations of plasmonic polymer solar cells (PSCs) incorporating a disordered array of non-uniform sized plasmonic nanoparticles (NPs) impose a prohibitively long-time and complex computational demand. To surmount this limitation, we present a novel semi-analytical modeling, which dramatically reduces computational time and resource consumption and yet is acceptably accurate. For this purpose, the optical modeling of active layer-incorporated plasmonic metal NPs, which is described by a homogenization theory based on a modified Maxwell–Garnett-Mie theory, is inputted in the electrical modeling based on the coupled equations of Poisson, continuity, and drift–diffusion. Besides, our modeling considers the effects of absorption in the non-active layers, interference induced by electrodes, and scattered light escaping from the PSC. The modeling results satisfactorily reproduce a series of experimental data for photovoltaic parameters of plasmonic PSCs, demonstrating the validity of our modeling approach. According to this, we implement the semi-analytical modeling to propose a new high-efficiency plasmonic PSC based on the PM6:Y6 PSC, having the highest reported power conversion efficiency (PCE) to date. The results show that the incorporation of plasmonic NPs into PM6:Y6 active layer leads to the PCE over 18%.

Experimental Validation of Forced Response Methods in a Multi-Stage Axial Turbine

2018 ◽  
Author(s):  
Thomas Hauptmann ◽  
Christopher E. Meinzer ◽  
Joerg R. Seume
Keyword(s):  
Experimental Data ◽  
Vibration Amplitude ◽  
Turbine Blades ◽  
Service Condition ◽  
Sensitivity Study ◽  
Forced Response ◽  
Tip Clearance ◽  
Computational Time ◽  
Reference Case ◽  
Axial Turbine

Depending on the in service condition of jet engines, turbine blades may have to be replaced, refurbished, or repaired in the course of an engine overhaul. Thus, significant changes of the turbine blade geometry can be introduced due to regeneration and overhaul processes. Such geometric variances can affect the aerodynamic and aeroelastic behavior of turbine blades. One goal in the development of the regeneration process is to estimate the aerodynamic excitation of turbine blades depending on these geometric variances caused during the regeneration. Therefore, this study presents an experimentally validated comparison of two methods for the prediction of forced response in a multistage axial turbine. Two unidirectional fluid structure interaction (FSI) methods, a time-linearized and a time-accurate with a subsequent linear harmonic analysis, are employed and the results validated against experimental data. The results show that the vibration amplitude of the time-linearized method is in good agreement with the experimental data and, also requires lower computational time than the time-accurate FSI. Based on this result, the time-linearized method is used to perform a sensitivity study of the tip clearance size of the last rotor blade row of the five stage axial turbine. The results show that an increasing tip clearances size causes an up to 1.35 higher vibration amplitude compared to the reference case, due to increased forcing and decreased damping work.

scholarly journals Use of an Inverse Method for the Design of High Efficiency Compressor and Turbine Blades With Large Change in Radius

1984 ◽  
Author(s):  
G. Meauzé ◽  
A. Lesain
Keyword(s):  
Inverse Method ◽  
High Efficiency ◽  
Radial Flow ◽  
Turbine Blades ◽  
Large Change ◽  
Airfoil Optimization ◽  
Time Marching ◽  
Flow Compressor ◽  
Compressor And Turbine Blades ◽  
Made In

Extension of the time-marching computations of flows in 2-D blade cascades to the case of cascades with variable radius and stream tube thickness. One of the specific cases analyzed is that of purely radial cascades. Direct and inverse calculations are made, in non-viscous subsonic or supersonic flows, with or without shock waves. Examples of the design of high efficiency airfoil optimization for radial flow compressor rotors or Stators or inward flow turbine inlet guide vanes are presented.

scholarly journals Accurate loads and velocities on low solidity wind turbines using an improved Blade Element Momentum model

2020 ◽  
Author(s):  
Yassine Ouakki ◽  
Abdelaziz Arbaoui
Keyword(s):  
Drag Force ◽  
Wind Turbines ◽  
Solution Method ◽  
Turbine Blades ◽  
Accurate Prediction ◽  
Accurate Estimation ◽  
Complex Nature ◽  
Momentum Theory ◽  
Far Wake ◽  
Blade Element

Abstract. The accurate prediction of loadings and velocities on a wind turbine blades is essential for the design and optimization of wind turbines rotors. However, the classical BEM still suffer from an inaccurate prediction of induced velocities and loadings, even if the classical correction like stall delay effect and tip loss correction are used. For low solidity rotors, the loadings are generally over-predicted in the tip region, since the far wake expansion is not accurately accounted for in the one-dimensional (1D) momentum theory. The 1D dimensional momentum theory supposes that the far wake axial induction is equal to twice the axial induction in the rotor plane, which results in an under-estimation of the axial induction factor in the tip region. Considering the complex nature of the flow around a rotating blade, the accurate estimation of 3D effects is still challenging, since most stall delay models still often tend to under-predict or over-predict the loadings near the root region. As for the solution method for the classical BEM equation, the induced velocities are computed accounting for the drag force. However, according to the Kutta-Joukowski theorem, the induced velocities on a blade element are only created by lift force. Accounting for drag force when solving the BEM will result in an over-estimation of the axial induction factor, while the tangential induction factor is under-estimated. To improve the accuracy of the BEM method, in this paper, the 1D momentum theory is corrected using a new far wake expansion model to take into account the radial flow effect. The blade element theory is corrected for three-dimensional effects through an improved stall delay model. An improved solution method for the BEM equations respecting the Kutta-Joukowski theorem is proposed. The improved BEM model is used to estimate the aerodynamic loads and velocities on the National Renewable Energy Laboratory Phase VI rotor blades. The results of this study show that the proposed BEM model gives an accurate prediction of the loads and velocities compared to the classical BEM model.

scholarly journals A Modified High Voltage Gain SEPIC Based DC-DC Converter with Continuous Conduction Mode

2020 ◽  
Vol 6 (12) ◽  
pp. 268-274
Author(s):  
G.Vijaykumar and Dr.V.Geetha
Keyword(s):  
High Voltage ◽  
High Efficiency ◽  
Input Voltage ◽  
Voltage Gain ◽  
Pv System ◽  
Operating Modes ◽  
High Voltage Gain ◽  
Voltage Stress ◽  
High Output Voltage ◽  
High Output

A high voltage gain modified SEPIC converter is proposed in this paper. This proposed converter has many advantages i.e., high output voltage, lower voltage stress, high efficiency, voltage gain is high without any coupled inductor and transformer, continuous input current. Thus, there is no overshoot voltage at turn-off process for switches. By using single switches, the CCM mode operation can be easily controlled by this converter, so control system is simple and also wide output values is obtained only by modifying the duty cycle. This modified converter has lower components than conventional converter. The operating modes and design of modified converter are discussed. The output power of this converter is 6 watts. By this converter, this converter capable of developing the two and half times of input voltage. The PV system also used this converter to develop high voltage gain. This high voltage gain is achieved by using MATLAB/SIMULIMK platform.

scholarly journals Electromechanical Modeling and Simulation of Piezoelectric Vibration based Energy Harvester Interfaced with MPPT based Electrical Circuit using Matlab Simulink

2019 ◽  
Vol 8 (2S11) ◽  
pp. 36-40
Keyword(s):  
Energy Harvester ◽  
High Efficiency ◽  
Electrical Circuit ◽  
Vibration Energy Harvester ◽  
Matlab Simulink ◽  
Electromechanical Model ◽  
Wind Vibration ◽  
Long Time ◽  
Piezoelectric Vibration ◽  
High Output

Wind vibration based energy harvester using piezoelectric material has been of great concern to researchers for a long time for low power generation and applications. In this paper, wind generated vibrations are used to develop electromechanical model of piezoelectric vibration energy harvester to generate electrical output using MATLAB simulink and comparision has been drawn between an electromechanical model of piezoelectric harvester interfaced with P&O MPPT based electrical model and without it. It has been found that overall model with MPPT provides high output with high efficiency

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