Flow Field Numerical Optimization of a Large Self-Dumping Truck Hydraulic Tank

2011 ◽  
Vol 94-96 ◽  
pp. 1991-1997 ◽  
Author(s):  
Shui Chang Liu ◽  
Li Fu Li ◽  
Zheng Qi Gu ◽  
Yong Zhang
Keyword(s):  
Heat Exchange ◽  
Flow Field ◽  
Heat Balance ◽  
Numerical Optimization ◽  
Temperature Fluctuations ◽  
Point Temperature ◽  
Hydraulic Oil ◽  
Balance Calculation ◽  
Exit Temperature ◽  
Cfd Method

Various return oil channels of a large self-dumping truck hydraulic tank don’t work synchronously brings the exit temperature fluctuations, traditional heat balance calculation can’t get some point temperature in tank, so it can’t be used to analyze temperature fluctuations. Selecting RNG k-εturbulent model and using CFD method，this paper analyzes flow field in the hydraulic tank of a certain large self-dumping truck at first, then according the principle of enhancing heat exchange, proposes two structure improved schemes, and contrasts the simulation result of two schemes, The results show that the two improved schemes reduce the tank exit temperature fluctuations and the high local temperature at different degrees, and the temperature fluctuations reduce range of the best scheme is 86.51% when the initial hydraulic oil temperature is 40°C.

Heat Transfer in Gas-Insulated Bus Bars

2003 ◽  
Author(s):  
Jin-Ki Ham ◽  
Young-Ki Kim ◽  
Jin-Soo Kim ◽  
Seok-Hyun Song
Keyword(s):  
Natural Convection ◽  
Flow Field ◽  
Heat Balance ◽  
Single Phase ◽  
Field Analysis ◽  
Balance Calculation ◽  
Three Phase ◽  
Flow Field Analysis ◽  
Laminar Natural Convection ◽  
The Heat Balance

Numerical prediction and experimental verification of the temperature rise for a single-phase and a three-phase gas-insulated bus bar with current flow are investigated. Various heat generation rates possibly produced in the gas-insulated bus bar are calculated. To estimate the power loss caused by eddy current, the magnetic field analysis is carried out. The heat balance calculation solving the differential form of an energy balance equation with empirical relations is conducted by using the 5th order Runge-Kutta method. The various cases representing different geometries and current values are investigated by conducting the heat balance calculation. Three-dimensional numerical flow field analysis using finite volume method is performed for the different type of the bus bars. From the flow field analysis based on laminar natural convection, the temperature gradient in the current flowing direction caused by contact heat source is found for both single-phase and three-phase bus bars. In the experiments, temperature rises in each of conductor, contact part, and external tank are measured for a full-scale gas-insulated bus bar. The comparisons of the predicted values of the heat balance calculation and the numerical analyses to results of the experiments are made. From the comparisons, it is concluded that the temperature rise of a bus bar can be predicted quite well by performing laminar natural convection flow analyses.

scholarly journals Mathematical Model Describing the Coupled Heat Transfer in Effusion Cooled Combustor Walls

1997 ◽  
Author(s):  
M. Martiny ◽  
A. Schulz ◽  
S. Wittig
Keyword(s):  
Heat Transfer ◽  
Mathematical Model ◽  
Heat Exchange ◽  
Heat Balance ◽  
Film Cooling ◽  
Parameter Study ◽  
Cold Side ◽  
Dimensionless Parameters ◽  
Coupled Heat Transfer ◽  
Exit Temperature

A mathematical model to describe the coupled heat transfer in effusion-cooled combustor walls is presented. A heat balance with respect to the heat transfer with film cooling on the hot side, heat transfer on the cold side and heat exchange between the wall and the coolant inside the holes leads to a system of four equations for the unknown temperatures on the hot and cold side of the wall and for the inlet and exit temperature of the coolant. The model is validated with experimentally determined exit temperatures. A parameter study showing the influence of the major dimensionless parameters is performed.

Counter-current heat exchange in the respiratory passages: Effect on water and heat balance

1970 ◽  
Vol 9 (2) ◽  
pp. 263-276 ◽  
Author(s):  
Knut Schmidt-Nielsen ◽  
F.Reed Hainsworth ◽  
David E. Murrish
Keyword(s):  
Heat Exchange ◽  
Heat Balance ◽  
Counter Current ◽  
Current Heat

scholarly journals ON THE SOLUTION OF ENERGY BALANCE EQUATION SYSTEM TO PREDICT TEMPERATURE DISTRIBUTION IN THE BUILDING ELEMENTS WITH VENTILATED AIR GAP

2014 ◽  
Vol 21 (1) ◽  
pp. 21-30 ◽  
Author(s):  
Edmundas Monstvilas ◽  
Karolis Banionis ◽  
Jurga Poderytė ◽  
Raimondas Bliūdžius ◽  
Arūnas Burlingis
Keyword(s):  
Heat Exchange ◽  
Balance Equation ◽  
Heat Balance ◽  
Internal Surface ◽  
Equation System ◽  
Energy Balance Equation ◽  
Air Gap ◽  
Exchange Processes ◽  
Calculation Results ◽  
Thermal Indicators

The article presents the solution of heat balance equation system, describing heat exchange processes in ventilated envelopes, which was applied to derive formulas for the calculation of temperatures in the ventilated layers of the envelopes. The accurateness of the formulas was assessed by experimental research and analysis of the calculation results. During the process of heat exchange balance equation solution, the equations were simplified by introducing the following restriction into the derived formulas: they may only be applied for the ventilated envelopes with steel or similar coatings as their external layers, i.e. coatings having small heat capacity and minor difference between the external and internal surface temperatures. The derived formulas enable the calculation of the temperatures of the ventilated envelopes in the distance which does not exceed a half of the ventilated air gap length measuring from the air entrance into the gap. However, this restriction does not impede the estimation of the average thermal indicators of the ventilated envelopes.

scholarly journals Heat exchange performance optimization of a wheel loader cooling system based on computational fluid dynamic simulation

2018 ◽  
Vol 10 (11) ◽  
pp. 168781401880398 ◽  
Author(s):  
Chao Yu ◽  
Sicheng Qin ◽  
Yang Liu ◽  
Bosen Chai
Keyword(s):  
Heat Exchange ◽  
Flow Field ◽  
Thermal Management ◽  
Cooling System ◽  
Management Model ◽  
Maximum Deviation ◽  
Engine Compartment ◽  
Wheel Loader ◽  
Exchange Performance ◽  
Transmission Oil

This study establishes a thermal management model to improve the heat exchange performance and uniformity of the flow-field distribution in the engine compartment of a wheel loader. Flow-field analyses are performed for an XG956 wheel loader in a virtual wind tunnel using the combined engine compartment thermal management model and computational fluid dynamics. The Fluent calculations revealed various problems. For example, the inlet flow rate at both sides of the engine compartment is small, which accounts for about 8.5% of the total flow, and the flow uniformity of radiator becomes worse with the increase in the air flow. The original cooling system is improved based on the simulation results and then verified by field testing. A comparison of the test data with the simulations indicates that the values obtained using the thermal management model of the engine compartment are largely in agreement with the experimental values, with a maximum deviation of the heat transfer rate at the rated speed of 5.1%. The research method presented in this article could further help to increase the productivity of the non-road mobile machinery cooling system and lower design costs. The temperature of pressurized air, hydraulic oil, transmission oil, and engine cooling fluid decreased by 22.5%, 8.7%, 2.2%, and 8.4% in the improved loader, respectively.

scholarly journals The human heat balance in the city of Novi Sad (Serbia)

2012 ◽  
Vol 92 (4) ◽  
pp. 99-112
Author(s):  
Aleksandar Krajic
Keyword(s):  
Heat Exchange ◽  
Heat Balance ◽  
Meteorological Data ◽  
Balance Model ◽  
Human Organism ◽  
Health Resource ◽  
Weather Variables ◽  
Climatological Station ◽  
Novi Sad ◽  
The City

This analysis is based on the human heat balance according to the bioclimatic man-environment heat exchange model created by Krzysztof B?a?ejczyk. The final result of the human heat balance model points to biothermal weather situations for the outdoor recreational needs. In this analysis, middles daily meteorological data (of climatological station of Novi Sad) were used for two extreme months, January and July. In this work, it is analyzed two periods, the first is for 1992-2010. and the second is for year 2010. The aim is to show how weather can be evaluated for recreational needs which the health resource of Novi Sad and to point out the shortcomings when it comes to multi-year analysis. The objective of this article has been to present a bioclimatic analysis of city Novi Sad and how weather variables come together in order to give a climate meaning on human organism.

Experimental Studies of the Primary Zone Flow Field and Combustion Performance of a Triple Swirler Combustor

2005 ◽  
Author(s):  
Yunhui Peng ◽  
Quanhong Xu ◽  
Yuzhen Lin
Keyword(s):  
Flow Field ◽  
Experimental Studies ◽  
Fuel Injector ◽  
Lean Blowout ◽  
Combustion Performance ◽  
Primary Zone ◽  
Image Velocimetry ◽  
Aero Engine ◽  
Exit Temperature ◽  
Promising Solution

Improvement of the lean blowout limit and more uniform combustor exit temperature distribution are particularly desirable for future aero engine. A triple swirler combination plus an airblast fuel injector might be a promising solution. The design with the triple swirler plus the airblast fuel injector including design A and B was presented and investigated in this paper. Single rectangle sector module combustor was used in the experiment for lean blowout (LBO), and three cups rectangle sector combustor was used for pattern factor (PF) experiments. The LBO and PF experiment data were provided. The primary zone flow field was measured by PIV (Particle Image Velocimetry) under atmospheric pressure and temperature. The result showed that the design A was a promising design, and the primary jet played very important role for flow field of primary zone. The insight relation between flow field and combustion performance could be found out from this paper.

CFD-Based Hydrodynamic Analysis for a Ship Sailing Along a Bank in Restricted Waters

2013 ◽  
Vol 155 (A2) ◽  
Keyword(s):  
Flow Field ◽  
Physical Mechanism ◽  
Control Force ◽  
Hydrodynamic Analysis ◽  
Bank Effect ◽  
Ship Steering ◽  
Control Devices ◽  
Cfd Method ◽  
And Control ◽  
Water Depths

For a ship navigating along a bank in restricted waters, it is usually accompanied by obvious bank effect which may cause ship-bank collision. In order to avoid collision, it is necessary to provide control force and moment by using control devices such as a rudder. In this paper, CFD method is applied to numerically simulate the viscous flow around a ship appended with a rudder sailing along a bank. Systematical simulations are carried out for the hull-rudder system with different rudder angles at different ship-bank distances and water depths. The flow field features and the hydrodynamic forces of the hull-rudder system are obtained and analysed. This study is of significance for revealing the physical mechanism behind the bank effect and providing guidance for ship steering and control in restricted waters.

Theory and Application of Stage-by-Stage Evaluation for Steam Turbine State-Line

1984 ◽  
Vol 28 (04) ◽  
pp. 240-260
Author(s):  
Robert Latorre ◽  
Zisimos Mourelatos ◽  
Efstratios Nikolaidis
Keyword(s):  
Theoretical Model ◽  
Computer Program ◽  
Steam Turbine ◽  
Heat Balance ◽  
Standard Heat ◽  
Balance Calculation ◽  
Calculation Results ◽  
Design Case ◽  
The Heat Balance

A theoretical model of a steam turbine is formulated based on idealized Curtis and reaction stages to obtain expressions for a stage-by-stage evaluation of the turbine state line. Using typical stage geometries and corrections a computer program was developed to size the turbine and evaluate its state line at design conditions. A comparison of the heat balance made with the stage-by-stage state line and the standard heat balance is presented. For the design case of 30 000 shp it is shown that the differences in the heat balance calculation results are within ±0.5 percent.

Precision Compound Sand Control Screen Internal Flow Field of the CFD Simulation

2014 ◽  
Vol 644-650 ◽  
pp. 4682-4685
Author(s):  
Zhi Jian Wang ◽  
Tian Zhu Zhang ◽  
Jin Shang ◽  
Metsakeu Kong Evariste
Keyword(s):  
Flow Field ◽  
Cfd Simulation ◽  
Internal Flow ◽  
Screen Effect ◽  
Theoretical Support ◽  
Sand Control ◽  
Porous Media Model ◽  
Speed Change ◽  
Cfd Method ◽  
Production Losses

In this paper, calculating fluid dynamics (CFD) method is utilized for analyzing the precision compound sand control screen internal flow field so as to establish appropriate models. During this numerical calculation, by using the - turbulence model is used to simulate the resistance characteristics under different working conditions when crude oil flows through precision compound sand control screen, analyze its speed change rule, flow path and pressure distribution, etc. The use of porous media model to simulate the resistance of the oil screen effect, the oil screen is replaced by the porous jump surface to simulate the strainer of pressure drop. To screen sand control performance and reduce the flow resistance to provide theoretical support, make the reservoir production losses to a minimum.

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