scholarly journals Influence of Flow Divider on Overall Efficiency of a Hydrostatic Drivetrain of a Skid-Steer All-Wheel Drive Multiple-Axle Vehicle

Energies ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3560
Author(s):  
Mirosław Przybysz ◽  
Marian Janusz Łopatka ◽  
Marcin Małek ◽  
Arkadiusz Rubiec
Keyword(s):  
Pressure Drop ◽  
Performance Characteristics ◽  
Motor Circuit ◽  
Low Speed ◽  
Flow Divider ◽  
Wheel Drive ◽  
Vehicle Mobility ◽  
Overall Efficiency

The efficiency of a skid-steer, all-wheel drive, multiple-axle vehicle with a hydrostatic drivetrain equipped with low-speed motors when it operates on soft terrain was studied. A flow divider enables a single pump to simultaneously power more than one motor circuit with different pressures in each. It prevents kinematic discrepancy and improves vehicle mobility. There are two types of flow divider: spool type and gear type, where each type has its own set of performance characteristics, such as flow range, pressure drop, accuracy and application parameters. In the present work, the influence of the characteristics of both types of flow divider on overall vehicle driveline efficacy is described.

The Effect of Inlet Distortion on the Performance Characteristics of a Centrifugal Compressor

1983 ◽  
Vol 105 (2) ◽  
pp. 223-230 ◽  
Author(s):  
I. Ariga ◽  
N. Kasai ◽  
S. Masuda ◽  
Y. Watanabe ◽  
I. Watanabe
Keyword(s):  
Centrifugal Compressor ◽  
Total Pressure ◽  
Performance Characteristics ◽  
Performance Tests ◽  
Velocity Measurements ◽  
Test Rig ◽  
Low Speed ◽  
Inlet Distortion ◽  
Surge Margin ◽  
The Given

The present paper concerns itself with the effects of total pressure (and thus velocity) distortion on performance characteristics and surge margin of centrifugal compressors. Both radial and circumferential distortions were investigated. The performance tests as well as the velocity measurements within the impeller passages were carried out with a low-speed compressor test rig with the inlet honeycomb as the distortion generators and compared with the case of “no distortion” as a datum. The results indicated that the inlet distortion exerted unfavorable influences on the efficiency and the surge margin of the given compressor, though the influence of the radial distortion was much stronger than that of the circumferential one. Various distortion indices were further examined in order to correlate the performance to the inlet distortion.

scholarly journals The Effect of Inlet Distortion on the Performance Characteristics of a Centrifugal Compressor

1982 ◽  
Author(s):  
I. Ariga ◽  
N. Kasai ◽  
S. Masuda ◽  
Y. Watanabe ◽  
I. Watanabe
Keyword(s):  
Centrifugal Compressor ◽  
Total Pressure ◽  
Performance Characteristics ◽  
Performance Tests ◽  
Velocity Measurements ◽  
Test Rig ◽  
Low Speed ◽  
Inlet Distortion ◽  
Surge Margin ◽  
The Given

The present paper concerns itself with the effects of total pressure (and thus velocity) distortion on performance characteristics and surge margin of centrifugal compressors. Both radial and circumferential distortions were investigated. The performance tests as well as the velocity measurements within the impeller passages were carried out with a low speed compressor test rig with the inlet honeycomb as the distortion generators and compared with the case of “no distortion” as a datum. The results indicated that the inlet distortion exerted unfavorable influences on the efficiency and the surge margin of the given compressor, though the influence of the radial distortion was much stronger than that of the circumferential one. Various distortion indices were further examined in order to correlate the performance to the inlet distortion.

An Experimental Investigation of Butterfly Valve Performance Downstream of an Elbow

1991 ◽  
Vol 113 (1) ◽  
pp. 81-85 ◽  
Author(s):  
M. J. Morris ◽  
J. C. Dutton
Keyword(s):  
Experimental Investigation ◽  
Pressure Drop ◽  
Mass Flow ◽  
Performance Characteristics ◽  
Flow Coefficient ◽  
Butterfly Valve ◽  
Operating Characteristics ◽  
Drop Mass ◽  
Torque Coefficient ◽  
Aerodynamic Torque

The results of an experimental investigation concerning the operating characteristics of a butterfly valve downstream of a mitered elbow are reported. Primary emphasis is given the influences of valve disk angle, valve/elbow spacing, and valve/elbow orientation on the dimensionless pressure drop, mass flow coefficient, and aerodynamic torque coefficient characteristics of the valve. The results show that when the valve is located two pipe diameters downstream of the elbow, the performance characteristics are substantially affected by the relative valve/elbow orientation. However, at a spacing of eight diameters the effect of the elbow on the valve operating characteristics is small.

Aerodynamic and Performance Analysis of Representatives of One Century of Low Speed Aircraft

2014 ◽  
Vol 1016 ◽  
pp. 400-404
Author(s):  
Luciano Magno Fragola Barbosa ◽  
Paulo H. Iscold A. de Oliveira
Keyword(s):  
Performance Analysis ◽  
Comparative Study ◽  
Low Power ◽  
Reference Data ◽  
Performance Characteristics ◽  
Wing Loading ◽  
Low Speed ◽  
Data Basis ◽  
Low Weight ◽  
And Performance

This work presents a comparative study of aerodynamic and performance characteristics of relevant examples of low speed aircraft that have been built and flown between 1890 and 1990. As speed is related to aircraft mass and wing loading and power, the aircraft analyzed present low weight, low wing loading and low power. To generate this study a set of tools have been developed, which are specifically aimed to slow and light aircraft. One additional goal of the study is to obtain a consistent reference data basis - by using the developed tools to analyze existing aircraft - prior to use these tools in new designs with the features of low speed, low wing loading and low power.

scholarly journals Numerical Simulation of the Performance Characteristics of the Hybrid Closed Circuit Cooling Tower

2008 ◽  
Vol 13 (1) ◽  
pp. 89-101 ◽  
Author(s):  
M. M. A. Sarker ◽  
E. Kim ◽  
G. C. Moon ◽  
J. I. Yoon
Keyword(s):  
Pressure Drop ◽  
Experimental Measurement ◽  
Cooling Tower ◽  
Cfd Simulation ◽  
Air Flow ◽  
Flow Distribution ◽  
Cooling Capacity ◽  
Performance Characteristics ◽  
Closed Circuit ◽  
Flow Rates

The performance characteristics of the Hybrid Closed Circuit Cooling Tower (HCCCT) have been investigated applying computational fluid dynamics (CFD). Widely reported CFD techniques are applied to simulate the air-water two phase flow inside the HCCCT. The pressure drop and the cooling capacity were investigated from several perspectives. Three different transverse pitches were tested and found that a pitch of 45 mm had lower pressure drop. The CFD simulation indicated that when air is supplied from the side wall of the HCCCT, the pressure drop can be over predicted and the cooling capacity can be under predicted mainly due to the non-uniform air flow distribution across the coil bank. The cooling capacity in wet mode have been calculated with respect to wet-bulb temperature (WBT) and cooling water to air mass flow rates for different spray water volume flow rates and the results were compared to the experimental measurement and found to conform well for the air supply from the bottom end. The differences of the cooling capacity and pressure drop in between the CFD simulation and experimental measurement in hybrid mode were less than 5 % and 7 % respectively for the uniform air flow distribution.

Computer Controlled Integrated Steering / Drive System for Vehicles

1996 ◽  
Author(s):  
D. B. Blair ◽  
I. J. Spark
Keyword(s):  
Essential Feature ◽  
Drive System ◽  
Steering Wheel ◽  
Low Speed ◽  
Left Hand ◽  
Right Hand ◽  
Wheel Drive ◽  
Speed Stability ◽  
Computer Controlled ◽  
Four Wheel Drive

Abstract This paper discusses how a computer controlled four-wheel-steering (4WS) system can be used to increase the ability, namely low speed stability and traction as well as increased manoeuvrability of four-wheel-drive (4WD) vehicles. The essential feature of the integrated 4WS/4WD vehicle is that the path of the vehicle is selected via a joy stick or steering wheel, and a computer then controls the drive system of the two right hand wheels independently of the two left hand wheels, along with the positive rotation of the four wheels about vertical axes to the appropriate angles. Previous work by Spark and Besselink (1994a) relating to two wheel steering (2WS) / two wheel drive (2WD) systems will also be discussed briefly and expanded.

scholarly journals Effects of Pressure Drops on the Performance Characteristics of Air Standard Otto Cycle

2011 ◽  
Vol 2011 ◽  
pp. 1-7 ◽  
Author(s):  
Mahmoud Huleihil
Keyword(s):  
Pressure Drop ◽  
Constant Pressure ◽  
Performance Characteristics ◽  
Maximum Efficiency ◽  
Maximum Pressure ◽  
Otto Cycle ◽  
Pressure Drops ◽  
Internal Irreversibility ◽  
Expansion Model ◽  
Engine Size

The effects of pressure drops on the performance characteristics of the air standard Otto cycle are reported. The pressure drops are assumed as constant values independent of the engine size. It has been shown that the pressure drops to about 60% of the maximum pressure in the ideal cycle (Curto-Risso et al., 2008). Three different models are studied: constant pressure model, reversible adiabatic expansion model and polytropic expansion model. The findings of this study show that, at this level of pressure drop, the maximum efficiency of the Otto cycle is reduced by 15% approximately based on the constant pressure model. The combined effect of pressure drop with other modes of irreversibility, for example, internal irreversibility and heat leaks, could reduce the maximum efficiency into very low values (approximately 30%). The reversible adiabatic model predicts reduction of 13% in efficiency at 40% pressure drop levels but at the price of zero power production. On the other hand, the polytropic expansion model predicts 40% reduction in efficiency for the same level of pressure drop (40%). All three models show that the power output is very sensitive to pressure drop.

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