KINEMATICS OF MULTI-STAGE MATCHING GEARBOXES FOR HYDRODINAMIC TORQUE CONVERTERS

2021 ◽  
Vol 75 (4) ◽  
pp. 33-42
Author(s):  
Agureev Igor Evgen'evich ◽  
◽  
Sergeev Alexander Leonidovich ◽  
Trushin Nikolay Nikolaevich ◽  
◽  
...  
Keyword(s):  
Torque Converter ◽  
Operating Conditions ◽  
Design Solution ◽  
Multi Stage ◽  
Wide Range ◽  
Torque Converters ◽  
Stage Matching ◽  
External Loads ◽  
Current Operating

The study offers a design solution for online capacity adjustment of hydrodynamic torque converter powertrains. It is proposed to install a step-less speed drive or multistage matching gearbox between the engine and the torque converter to adjust the powertrain properties on the move depending on the current operating conditions. We propose the matching device arrange-ments. The solutions can be used in buses, trucks, tractors, diesel locomotives, etc. that operate in a wide range of external loads.

Influence of Stator Blade Geometry on Torque Converter Cavitation

2017 ◽  
Vol 140 (4) ◽  
Author(s):  
Cheng Liu ◽  
Wei Wei ◽  
Qingdong Yan ◽  
Brian K. Weaver ◽  
Houston G. Wood
Keyword(s):  
High Speed ◽  
Torque Converter ◽  
Operating Conditions ◽  
Hydrodynamic Performance ◽  
Speed Ratio ◽  
Capacity Loss ◽  
Wide Range ◽  
Stator Blade ◽  
Torque Converters ◽  
Blade Geometry

Cavitation in torque converters may cause degradation in hydrodynamic performance, severe noise, or even blade damage. Researches have highlighted that the stator is most susceptible to the occurrence of cavitation due to the combination of high flow velocities and high incidence angles. The objective of this study is to therefore investigate the effects of cavitation on hydrodynamic performance as well as the influence of stator blade geometry on cavitation. A steady-state homogeneous computational fluid dynamics (CFD) model was developed and validated against test data. It was found that cavitation brought severe capacity constant degradation under low-speed ratio (SR) operating conditions and vanished in high-speed ratio operating conditions. A design of experiments (DOE) study was performed to investigate the influence of stator design variables on cavitation over various operating conditions, and it was found that stator blade geometry had a significant effect on cavitation behavior. The results show that stator blade count and leaning angle are important variables in terms of capacity constant loss, torque ratio (TR) variance, and duration of cavitation. Large leaning angles are recommended due to their ability to increase the cavitation number in torque converters over a wide range of SRs, leading to less stall capacity loss as well as a shorter duration of cavitation. A reduced stator blade count is also suggested due to a reduced TR loss and capacity loss at stall.

scholarly journals Simple Design Solution for Harsh Operating Conditions: Redesign of Conveyor Transfer Station with Reverse Engineering and DEM Simulations

Energies ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 4008
Author(s):  
Błażej Doroszuk ◽  
Robert Król ◽  
Jarosław Wajs
Keyword(s):  
Reverse Engineering ◽  
Laser Scanning ◽  
Design For Manufacturing ◽  
Operating Conditions ◽  
Design Solution ◽  
Dem Simulations ◽  
Transfer Station ◽  
Transfer Stations ◽  
Dem Model ◽  
Current Operating

This paper addresses the problem of conveyor transfer station design in harsh operating conditions, aiming to identify and eliminate a failure phenomenon which interrupts aggregate supply. The analyzed transfer station is located in a Polish granite quarry. The study employs laser scanning and reverse engineering methods to map the existing transfer station and its geometry. Next, a discrete element method (DEM) model of granite aggregate has been created and used for simulating current operating conditions. The arch formation has been identified as the main reason for breakdowns. Alternative design solutions for transfer stations were tested in DEM simulations. The most uncomplicated design for manufacturing incorporated an impact plate, and a straight chute has been selected as the best solution. The study also involved identifying areas of the new station most exposed to wear phenomena. A new transfer point was implemented in the quarry and resolved the problem of blockages.

scholarly journals Predicting the Onset of Cavitation in Automotive Torque Converters—Part II: A Generalized Model

2008 ◽  
Vol 2008 ◽  
pp. 1-8 ◽  
Author(s):  
D. L. Robinette ◽  
J. M. Schweitzer ◽  
D. G. Maddock ◽  
C. L. Anderson ◽  
J. R. Blough ◽  
...  
Keyword(s):  
Dimensional Analysis ◽  
Torque Converter ◽  
Fundamental Principle ◽  
Empirical Models ◽  
Operating Conditions ◽  
Design Parameters ◽  
Test Results ◽  
Linear Regression Technique ◽  
Torque Converters ◽  
Onset Of Cavitation

The objective of this investigation was to develop a dimensionless model for predicting the onset of cavitation in torque converters applicable to general converter designs. Dimensional analysis was applied to test results from a matrix of torque converters that ranged from populations comprised of strict geometric similitude to those with more relaxed similarities onto inclusion of all the torque converters tested. Stator torque thresholds at the onset of cavitation for the stall operating condition were experimentally determined with a dynamometer test cell using nearfield acoustical measurements. Cavitation torques, design parameters, and operating conditions were resolved into a set of dimensionless quantities for use in the development of dimensionless empirical models. A systematic relaxation of the fundamental principle of dimensional analysis, geometric similitude, was undertaken to present empirical models applicable to torque converter designs of increasingly diverse design parameters. A stepwise linear regression technique coupled with response surface methodology was utilized to produce an empirical model capable of predicting stator torque at the onset of cavitation with less than 7% error for general automotive torque converter designs.

scholarly journals Measurements of Strain on 310 mm Torque Converter Turbine Blades

2004 ◽  
Vol 10 (1) ◽  
pp. 55-63
Author(s):  
P. O. Sweger ◽  
C. L. Anderson ◽  
J. R. Blough
Keyword(s):  
Turbine Blade ◽  
Turbine Blades ◽  
Torque Converter ◽  
Operating Conditions ◽  
Surface Strain ◽  
Speed Ratio ◽  
Constant Input ◽  
Wide Range ◽  
Blade Tip ◽  
Input Torque

An automotive torque converter was tested in order to determine the effect of converter operating condition and turbine blade design on turbine blade strain in the region of the inlet core tab restraint. The converter was operated over a wide range of speed ratios (0 to 0.95) at constant input torque and a stall condition for two input torques. Foil-type strain gages in combination with wireless microwave telemetry were used to measure surface strain on the turbine blade. Strain measurements were made on two turbine blade designs.The steady component of strain over the range of speed ratios suggests the effect of both torque loading and centrifugal loading on the turbine blade tip. The unsteady strain was greatest at stall condition and diminished as speed ratio increased. Greater input torque at stall condition resulted in both greater steady strain and greater unsteady strain. The spectral distribution of strain over the range of tested speed ratios displayed an increase in low-frequency broadband fluctuations near stall condition. A blade-periodic event is observed which correlates to the pump-blade passing frequency relative to the turbine rotating frame. Reducing the blade-tip surface area and increasing the inlet-tab root radius reduced the range of steady strain and magnitude of unsteady strain imposed near the inlet core tab restraint over the range of operating conditions.

An Innovative Device for Passive Control of Surge in Industrial Compression Systems

2000 ◽  
Author(s):  
Gianmario L. Arnulfi ◽  
Pietro Giannattasio ◽  
Diego Micheli ◽  
Piero Pinamonti
Keyword(s):  
Passive Control ◽  
Experimental Tests ◽  
Control Device ◽  
Operating Conditions ◽  
Compression System ◽  
Multi Stage ◽  
Lumped Parameter ◽  
Wide Range ◽  
Optimal Values ◽  
Parameter Approach

The present paper reports a numerical-experimental study on the dynamic behaviour of a compression system based on a multi-stage centrifugal blower and fitted with an innovative device for the dynamic suppression of surge instability. The control device is of passive type and is based on the aeroelastic coupling of the basic compression system with a hydraulic oscillator. The controlled system is modelled at first by using a non-linear lumped parameter approach. The simulated system dynamics within a wide range of operating conditions allows a parametric analysis to be performed and the optimal values of the control parameters to be singled out. Such optimal values are then used to design the hydraulic oscillator, which results in a technically feasible and very simple configuration. Finally, experimental tests are carried out on the compression plant with and without the passive control device, which demonstrate the effectiveness of the proposed control system in suppressing surge instabilities, at least within the limits predicted by the numerical simulation.

Performance Measurements in Large and Small Scale Multi-Stage Axial Compressors

1997 ◽  
Author(s):  
Ulrich Waitke ◽  
Michael Ladwig
Keyword(s):  
Detailed Comparison ◽  
Operating Conditions ◽  
Small Scale ◽  
Scaling Effects ◽  
Performance Measurements ◽  
Test Rig ◽  
Design Data ◽  
Multi Stage ◽  
Compressor Performance ◽  
Stage Matching

During the commissioning of the prototype of the sequential combustion turbine GT24 extensive measurements of the compressor performance at design- and off-design-operation were accomplished besides the investigation of the other components of the GT. While the compressor performance at design operating conditions was as expected the data obtained showed some unexpected deviations from previously performed measurements of a 1/3-scale test rig of the low pressure compressor. This paper summarizes the results of the measurements and presents a detailed comparison between the measured performance of the GT compressor, the design data and the test rig. The discussion is focused on the influence of scaling effects on the aerodynamic performance and stage matching with particular emphasis on the Reynolds Number influence at different aerodynamic speeds. Furthermore some aspects of the starting behavior of the compressor are presented.

scholarly journals A Wide-Range Axial-Flow Compressor Stage Performance Model

1992 ◽  
Author(s):  
Gregory S. Bloch ◽  
Walter F. O’Brien
Keyword(s):  
Axial Flow ◽  
Operating Conditions ◽  
System Response ◽  
Compressor Stage ◽  
Operating Characteristics ◽  
Compression System ◽  
Axial Flow Compressor ◽  
Multi Stage ◽  
Wide Range ◽  
Flow Compressor

Dynamic compression system response is a major concern in the operability of aircraft gas turbine engines. Multi-stage compression system computer models have been developed to predict compressor response to changing operating conditions. These models require a knowledge of the wide-range, steady-state operating characteristics as inputs, which has limited their use as predicting tools. The full range of dynamic axial-flow compressor operation spans forward and reversed flow conditions. A model for predicting the wide flow range characteristics of axial-flow compressor stages was developed and applied to a 3-stage, low-speed compressor with very favorable results and to a 10-stage, high-speed compressor with mixed results. Conclusions were made regarding the inception of stall and the effects associated with operating a stage in a multistage environment. It was also concluded that there are operating points of an isolated compressor stage that are not attainable when that stage is operated in a multi-stage environment.

Parametric Analysis and Optimization of Inlet Inflection Angle in Torque Converters

2013 ◽  
Author(s):  
Cheng Liu ◽  
Alexandrina Untaroiu ◽  
Houston G. Wood ◽  
Qingdong Yan ◽  
Wei Wei
Keyword(s):  
Experimental Data ◽  
Parametric Analysis ◽  
Deflection Angle ◽  
Design Procedure ◽  
Optimization Procedure ◽  
Torque Converter ◽  
Operating Conditions ◽  
Design Quality ◽  
Torque Converters ◽  
Improved Design

Torque converters are widely used in all means of transportations, such as cars, buses, trucks, and the list can go on. Since power is transmitted via fluid, the blade geometry which forms the flow passages is crucial to torque converter performance. The inlet deflection angle is an important blade design parameter with respect to both performance and manufacturability of torque converters. In the conventional design procedure, inlet deflection angle is often given by the designer’s experience or is selected based on experimental data if available. This study presents a method of optimizing the inlet deflection angle for torque converters and provides a series of non-inferior solutions for the decision maker to select from. The advantages of the method proposed consist of improved design quality and significantly shorter design cycle. A combination of computational analysis and global optimization algorithm was used in this study. A torque converter base model was evaluated using computational fluid dynamics for predicting its performance. The proper grid density and turbulence model were selected through correlation to the experimental data available. The following tasks were automated and integrated to form a parameterized design loop: 1) torque converter flow field CAD modeling, 2) meshing, and 3) CFD simulations and results post-processing. Selecting peak efficiency, stall torque ratio and stall pump capacity factor as objective functions, a multi-objective genetic algorithm was included in the design loop to optimize the torque converter performance. The CFD results proved to be in good agreement with the experimental data over the range of operating conditions considered in this study. The influence of inlet deflection angle on the performance of torque converter was determined through a parametric analysis and a series of Pareto-optimal solutions were determined by the optimization procedure, which proved to improve the performance of the base model torque converter.

scholarly journals Improving Next-Generation Falling Particle Receiver Designs Subject to Anticipated Operating Conditions

2020 ◽  
Author(s):  
Brantley Mills ◽  
Reid Shaeffer ◽  
Lindsey Yue ◽  
Clifford K. Ho
Keyword(s):  
Thermal Performance ◽  
Thermal Efficiency ◽  
Waste Heat ◽  
Operating Conditions ◽  
Wall Material ◽  
Receiver Design ◽  
Next Generation ◽  
Cfd Models ◽  
Multi Stage ◽  
Wide Range

Abstract The thermal performance of a candidate next-generation falling particle receiver (FPR) is analyzed subject to various expected operating conditions. This receiver design was created from the result of an extensive optimization study and developed to support the Generation 3 Particle Pilot Plant (G3P3) project. Previous analysis demonstrated high thermal efficiencies for the receiver at nominal quiescent conditions, but further analysis was required to demonstrate that the receiver could maintain that thermal performance in a wide range of anticipated environments. In this study, the thermal efficiency was numerically evaluated using a CFD model for different wind conditions and shown to maintain a thermal efficiency above 83% for considered wind conditions. Moreover, the effect of radiative spillage from the incoming concentrated solar beam on the receiver exterior was investigated using ray tracing and CFD models. The exterior wall material temperature limits were not exceeded for the anticipated design power from the heliostats. Additional features were numerically explored including the addition of a chimney to capture particle fines and waste heat and a multi-stage concept to maximize curtain opacity. Particle fines of 10 μm were shown to preferentially flow into this chimney rather than out of the aperture, and the multi-stage design decreased radiative losses and minimized wall temperatures behind the particle curtain.

Comparison of Deterministic and Linear Cosine Spatial Filtering of Transmission Electron Micrographs

1972 ◽  
Vol 30 ◽  
pp. 596-597
Author(s):  
David A. Ansley
Keyword(s):  
Spherical Aberration ◽  
Focal Length ◽  
Chromatic Aberration ◽  
Spatial Filter ◽  
Operating Conditions ◽  
Objective Lens ◽  
List Type ◽  
Spatial Filters ◽  
Transmission Electron ◽  
Wide Range

The coherence of the electron flux of a transmission electron microscope (TEM) limits the direct application of deconvolution techniques which have been used successfully on unmanned spacecraft programs. The theory assumes noncoherent illumination. Deconvolution of a TEM micrograph will, therefore, in general produce spurious detail rather than improved resolution.A primary goal of our research is to study the performance of several types of linear spatial filters as a function of specimen contrast, phase, and coherence. We have, therefore, developed a one-dimensional analysis and plotting program to simulate a wide 'range of operating conditions of the TEM, including adjustment of the:(1) Specimen amplitude, phase, and separation(2) Illumination wavelength, half-angle, and tilt(3) Objective lens focal length and aperture width(4) Spherical aberration, defocus, and chromatic aberration focus shift(5) Detector gamma, additive, and multiplicative noise constants(6) Type of spatial filter: linear cosine, linear sine, or deterministic

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