scholarly journals THREE DIMENSIONAL SIMULATION OF OIL FLOW CHARACTERISTICS IN LUBRICATION SYSTEM OF ROTARY TILLAGE ENGINE

2021 ◽  
pp. 163-172
Author(s):  
Junxiang Gao ◽  
Xiaoliang Gao ◽  
Wei Zou
Keyword(s):  
Pressure Drop ◽  
Three Dimensional ◽  
Flow Characteristics ◽  
Lubricating Oil ◽  
Flow Index ◽  
Lubrication System ◽  
Pump Rotor ◽  
Oil Pump ◽  
Oil Flow ◽  
Dimensional Simulation

Taking the lubrication system of rotary tillage engine as the research object, this paper makes a three-dimensional simulation study on the oil flow characteristics in the lubricating oil passage. The oil supply of the oil pump shall be greater than the circulating oil required by the lubrication system to ensure the lubrication of the rotary cultivator. Lubrication system is an important part to ensure the reliability and durability of rotary cultivator. The key component to achieve its performance is the oil pump. The geometric model of lubricating oil flow field in rotary tiller lubrication system is established by using FLUENT software. The results show that the pressure drop in the lubricating oil passage of the main bearing is the largest under the same working conditions. In the oil passage of the cylinder head, the pressure drop of the front main oil passage is the largest and the oil discharge is the largest. Add 1.6mm oil pump rotor on the basis of the thickness of the original oil pump rotor, the oil flow at the connecting rod nozzle reaches the flow index of the original rotary cultivator, and there is no cylinder pulling phenomenon of the rotary cultivator.

Numerical Study of Large Diameter Butterfly Valve on Flow Characteristics

2011 ◽  
Vol 236-238 ◽  
pp. 1653-1657 ◽  
Author(s):  
Xiao Dong Wang ◽  
Jing Liang Dong ◽  
Tian Wang
Keyword(s):  
Pressure Drop ◽  
Flow Resistance ◽  
Numerical Study ◽  
Large Diameter ◽  
Three Dimensional ◽  
Flow Characteristics ◽  
Numerical Approach ◽  
Resistance Coefficient ◽  
Butterfly Valve ◽  
Dimensional Simulation

A numerical approach was used to investigate the flow characteristics around a butterfly valve with the diameter of 2108 mm by the commercial computational fluid dynamics (CFD) code FLUENT6.3. The simulation was carried out to predict flow field structure, flow resistance coefficient, hydrodynamics torque and so on, when the large diameter butterfly valve operated at various opening degrees. The three-dimensional simulation results shown that there are vortexes presented near valve back region as the opening degree smaller than 40 degree; the flow resistance coefficient reduces rapidly with the increasing of opening degree and the resistance coefficient is quite small as the angle larger than 50 degree; the hydrodynamic torque reduces with the increasing of opening degree and the hydrodynamic torque is smaller than 20% of maximum torque; the torque ratio and the pressure drop ratio are reduce with the increasing of opening degree, the pressure drop ratio reduces rapidly as the opening degree is smaller than 50 degree.

Three-Dimensional Simulation of Turbulent Rectangular and Square Impinging Jet Flows

2004 ◽  
Author(s):  
Qingguang Chen ◽  
Zhong Xu ◽  
Yulin Wu ◽  
Yongjian Zhang
Keyword(s):  
Recirculation Zone ◽  
Three Dimensional ◽  
Flow Characteristics ◽  
Adverse Pressure Gradient ◽  
Impinging Jet ◽  
Boundary Layer Separation ◽  
Streamwise Velocity ◽  
Impinging Jets ◽  
Jet Flows ◽  
Dimensional Simulation

Flow characteristics of turbulent impinging jets issuing, respectively, from a rectangular and a square nozzles have been investigated numerically through the solution of three-dimensional Navier-Strokes equations in steady state. Two geometries with two nozzle-to-plate spacings of four and eight times of hydraulic diameters of the jet pipes, and two Reynolds numbers of 20000 and 30000 have been considered with fully developed inlet boundary conditions. An RNG based k–ε turbulence model and a deferred correction QUICK scheme in conjunction with the wall function method have been applied to the prediction of the flow fields within semi-confined spaces. A common feature revealed by the computational results is the presence of a toroidal recirculation zone around the jet. An adverse pressure gradient is found at the impingement surface downstream the stagnation point. Boundary layer separation will occur if the gradient is strong enough, and the separation manifests itself as a secondary recirculation zone at the surface. In addition, three-dimensional simulations reveal the existence of two and four pronounced streamwise velocity off-center peaks at the cross-planes near to the impingement plate, respectively, in the rectangular and square impinging jet flows. These peaks are found forming at the horizontal planes where the wall jets start forming accompanied by two or four pairs of counter-rotating vortex rings. It is believed that the formation of the off-center velocity peaks is due to the vorticity diffusion along the wall jet as the jet impinges on the target plate.

Optimization of the lubrication system in a turbocharged engine

2019 ◽  
Vol 33 (14n15) ◽  
pp. 1940011
Author(s):  
Cho-Yu Lee ◽  
Dani Joseph Veera ◽  
Huan-Yuan Chen ◽  
Jui-Hung Chang ◽  
Kao-Ruei Hung
Keyword(s):  
Pressure Drop ◽  
Flow Resistance ◽  
Engine Speed ◽  
System Optimization ◽  
Low Flow ◽  
Lubrication System ◽  
Mechanical Loss ◽  
Oil Pump ◽  
Oil Cooler ◽  
Base Engine

Lubricating the engine reciprocating components effectively against various engine speeds is significant for a proper lubrication system. This paper presents the lubrication system optimization of a twin cylinder 700 c.c. turbocharged engine. A couple of modifications were tested including correction of ducts misalignment, consistence diameter of ducts and replacement of a low flow resistance oil cooler. Compared to the base engine, experimental results prove that differential pressure (DP) between the oil pump and main oil gallery has been decreased to a minimum 19% and maximum 54% at engine speed between 2000 and 7000 rpm. The lower the pressure drop, the lower the flow resistance. Thus, mechanical loss has also been improved.

Three-dimensional simulation and experimental investigation of three-dimensional printed guiding devices on lattice-apron compact spinning

2020 ◽  
pp. 004051752098258
Author(s):  
Malik YH Saty ◽  
Nicholus Tayari Akankwasa ◽  
Jun Wang
Keyword(s):  
Experimental Investigation ◽  
Air Flow ◽  
Flow Analysis ◽  
Three Dimensional ◽  
Flow Characteristics ◽  
Yarn Properties ◽  
3D Printed ◽  
Dimensional Simulation ◽  
Compact Spinning ◽  
Set Up

The compact spinning system with a lattice apron utilizes air-flow dynamics to condense fibers in a bunch and enhance the yarn properties. One of the main challenges with this method is the lack of a comprehensive understanding of the air-flow field's effect in the condensing zone. This work presents a numerical and experimental investigation of the effects of three-dimensional (3D) printed guiding devices on the air-flow characteristics and yarn properties. Firstly, the 3D numerical model of the compact spinning system was set up based on the compact spinning machine geometrical dimensions. Secondly, different 3D prototypes were developed, simulated, and analyzed using computational fluid dynamics based on ANSYS software. The prototypes (A-type, B-type, and C-type), selected according to the simulation results, were then 3D printed to enable further experimental investigation. Air-flow analysis results in the air-suction flume area exhibiting a very high negative pressure, and the centerline zone was characterized by high velocity. Experimental results revealed that the three yarns spun with guiding devices had better strength, hairiness, and evenness than those spun without a guiding device. The model developed can be further improved and utilized for commercial purposes and is anticipated to improve compact spun yarn properties significantly.

The Effect of the Helical Inlet Port Design and the Shrouded Inlet Valve Condition on Swirl Generation in Diesel Engine

2017 ◽  
Vol 140 (3) ◽  
Author(s):  
Saleh Abo-Elfadl ◽  
A. Abd El-Sabor Mohamed
Keyword(s):  
Three Dimensional ◽  
Great Influence ◽  
Flow Characteristics ◽  
Volumetric Efficiency ◽  
Swirl Ratio ◽  
Inlet Valve ◽  
Inlet Port ◽  
Engine Cylinder ◽  
Port Design ◽  
Dimensional Simulation

Inlet port design has a great influence on swirl generation inside the engine cylinder. In this paper, two helical inlet ports having the same helix design were suggested. The first has an upper entrance, and the second has a side entrance. With the two ports, shrouded inlet valves having different conditions of shroud and orientation angles were used. Four shroud angles were used; they are 90 deg, 120 deg, 150 deg, and 180 deg. Also, four orientation angles were used; they are 0 deg, 30 deg, 60 deg, and 90 deg. Three-dimensional simulation model using the shear stress transport k–ω model was used for predicting the air flow characteristics through the inlet port and the engine cylinder in both intake and compression strokes. The results showed that the side entrance port produces swirl ratio higher than that of the upper entrance port by about 3.5%, while the volumetric efficiency is approximately the same for both ports. For both the ports, increasing the valve shroud angle increases the swirl ratio and reduces the volumetric efficiency. The maximum increments of swirl ratio relative to the ordinary valve case occur at valve conditions of 30–150 deg, 0–180 deg, and 30–180 deg. At these valve conditions, the swirl ratio values are 6.38, 6.72, and 6.95 at intake valve close (IVC) with percentage increments of 69.2%, 78.2%, and 84.4%, respectively. The corresponding values of the volumetric efficiency are 93.6, 92.5, and 91.2, respectively, with percentage decrements of 2.84%, 4%, and 5.7%, respectively.

Thermal Analysis of Lubricating Oil Flow Within a Wet-Disk Clutch

2000 ◽  
Author(s):  
Tien-Chien Jen ◽  
Dan Nemecek
Keyword(s):  
Thermal Analysis ◽  
Nusselt Number ◽  
Temperature Rise ◽  
Separation Of Variables ◽  
Three Dimensional ◽  
Lubricating Oil ◽  
Axial Position ◽  
Outlet Temperature ◽  
Wet Clutch ◽  
Oil Flow

Abstract A combined theoretical and experimental thermal analysis is conducted on the oil flow between the plates of a wet clutch during an extended slip engagement. An analytical model, using the separation of variables technique, is developed to simulate the temperature rise due to the non-conservative friction and relative motion between the steel plates and friction plates of the clutch. A three-dimensional numerical heat transfer and fluid flow model was developed to calculate the velocity and temperature profiles in the oil groove channel. Typical velocity profiles and temperature contours plots are demonstrated. Friction factor and Nusselt number are presented as functions of axial position. The experiment performed included a wet clutch instrumented with thermocouples and installed in a power-shift transmission where the temperature rise during one clutch engagement was measured. The total energy is then estimated by accounting for system inertia, torque and rotating speeds. Finally, the inlet, outlet temperature rises and the averaged Nusselt number of the oil groove are also presented.

The Emergency and Post-Lubrication System of TCA Turbochargers

2003 ◽  
Author(s):  
Ferdinand Werdecker ◽  
Hermann Link
Keyword(s):  
Pressure Control ◽  
Control Device ◽  
Maximum Temperature ◽  
Maximum Speed ◽  
Inlet Temperature ◽  
Lubrication System ◽  
Oil Pump ◽  
Oil Flow ◽  
Full Load Operation ◽  
Turbine Bearing

For the TCA turbocharger series a new emergency and post-lubrication system has been developed. This new system is supposed to maintain more than 10 seconds full load operation after an oil pump blackout. Moreover, the system has to efficiently supply oil for the run-out period and for cooling the bearings. In order to check this development target turbocharger TCA 77 was subjected to some tests. The tests were carried out under extreme conditions, i.e. maximum oil inlet temperature and minimum oil pressure. At maximum speed = 14900 rpm, toil = 60°C and poil = 1.3 bar the turbocharger continued its operation after stop of the oil pump without temperature increase in the bearings for 14 seconds before the pressure control device interrupted the fuel supply at 0.6 bar oil pressure. The pressurized part of the tank was sufficient for another 35 seconds during which the turbocharger speed dropped from 14900 rpm to a speed of about 7000 rpm. Both journal bearings and the axial bearings received oil for 2.5 minutes after pump stop. At this point the turbocharger still had a speed of 1500 rpm. After that the turbine bearing was cooled over a period of 1-1/2 hours by a geodetic driven oil flow. The maximum temperature at the turbine bearing of 180 °C (admissible approx. 220 °C) was achieved after 2 hours.

Modeling of Airflow in the Pharynx With Application to Sleep Apnea

1998 ◽  
Vol 120 (3) ◽  
pp. 416-422 ◽  
Author(s):  
B. Shome ◽  
L.-P. Wang ◽  
M. H. Santare ◽  
A. K. Prasad ◽  
A. Z. Szeri ◽  
...  
Keyword(s):  
Numerical Modeling ◽  
Sleep Apnea ◽  
Pressure Drop ◽  
Three Dimensional ◽  
Flow Characteristics ◽  
Transitional Flow ◽  
Subtle Change ◽  
Onset Of Turbulence ◽  
Wide Range ◽  
Sleep Apnea Treatment

A three-dimensional numerical modeling of airflow in the human pharynx using an anatomically accurate model was conducted. The pharynx walls were assumed to be passive and rigid. The results showed that the pressure drop in the pharynx lies in the range 200-500 Pa. The onset of turbulence was found to increase the pressure drop by 40 percent. A wide range of pharynx geometries covering three sleep apnea treatment therapies (CPAP, mandibular repositioning devices, and surgery) were modeled and the resulting flow characteristics were investigated and compared. The results confirmed that the airflow in the pharynx lies in the laminar-to-turbulence transitional flow regime and thus, a subtle change in the morphology caused by these treatment therapies can significantly affect the airflow characteristics.

Numerical Modeling of Unsteady Oil Film Motion Characteristics in Bearing Chambers

2015 ◽  
Vol 32 (3) ◽  
Author(s):  
Jingyu Zhao ◽  
Zhenxia Liu ◽  
Yaguo Lu ◽  
Jianping Hu
Keyword(s):  
Film Thickness ◽  
Theoretical Study ◽  
Rotation Speed ◽  
Three Dimensional ◽  
Lubricating Oil ◽  
Flow State ◽  
Oil Film ◽  
Model Based ◽  
Oil Flow ◽  
Motion Characteristics

AbstractTo obtain motion characteristics of the lubricating oil film on the aero-engine bearing chamber wall, a complete mathematical model based on theoretical study to solve three-dimensional unsteady oil film motion was established. On the basis of verifying the rationality of the computational model, the variations of the oil film thickness, velocity and temperature with the rotation speed and lubricating oil flow were analyzed and studied. The numerical results show that the following: In the stable oil film flow state, the oil film thickness shows a decreasing trend with increase in rotation speed and an increasing trend with increase in the lubricating oil flow. Particularly, comparison with the experimental work shows that the proposed numerical model based on theoretical study to solve unsteady oil film motion is a valuable technical means for the study of oil film movement mechanism and the design of actual bearing chamber.

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