Lubrication Effect of the Nozzle Layout for Arc Tooth Cylindrical Gears

2021 ◽  
pp. 1-25
Author(s):  
Shuai Mo ◽  
Changpeng zhou ◽  
Heyu Dang
Keyword(s):  
Fuel Injection ◽  
Nozzle Diameter ◽  
Comparison Analysis ◽  
Cylindrical Gear ◽  
Lubrication Performance ◽  
Simulation Calculation ◽  
Computational Fluid Dynamics Cfd ◽  
Oil Jet ◽  
Lubrication Effect ◽  
Lubrication Conditions

Abstract In order to study the influence of fuel injection nozzle arrangement on the lubrication effect of arc tooth cylindrical gear, a model of fuel injection lubrication was established, and computational fluid dynamics (CFD) software was used for simulation calculation. The focus on the influence of gear parameters, oil jet conditions and nozzle layout on gear lubrication performance is studied. The results show that reducing the oil jet distance not only improves the lubrication performance of the gear but also reduces the offset of the oil jet streamline. The reasonable of nozzle layout is the premise of ensuring better lubrication conditions, and the best nozzle layout scheme is obtained through data comparison analysis. The lubrication effect decreases when the nozzle angle is offset. The lubrication effect does not change when the nozzle is horizontally offset by a distance of 0.5 module in the direction of the pinion, and the lubrication performance is degraded when the distance exceeds 0.5 module. Finally, the influence of nozzle diameter on lubrication is analyzed, the lubrication effect is directly proportional to the nozzle diameter.

scholarly journals Numerical and Experimental Investigation of Oil-Guiding Splash Lubrication in Light Helicopter’s Reducers

Aerospace ◽  
2021 ◽  
Vol 8 (11) ◽  
pp. 345
Author(s):  
Mei Yin ◽  
Xi Chen ◽  
Yu Dai ◽  
Duan Yang ◽  
Lanjin Xu ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Experimental Investigation ◽  
Great Influence ◽  
Test Rig ◽  
Specific Test ◽  
Rotating Speed ◽  
Lubrication Performance ◽  
Computational Fluid Dynamics Cfd ◽  
Cfd Method ◽  
Oil Jet

Limited by the space and weight of the reducer, it is difficult to use traditional oil-jet lubrication and splash lubrication for a light helicopter, so an oil-guiding splash lubrication method is adopted as a research object in this paper. Firstly, the lubrication performance of the oil-guiding cylinder in the main reducer under different rotating speeds, oil levels, and flight attitudes is investigated based on the computational fluid dynamics (CFD) method. Then, a specific test rig is developed, and lubrication tests are carried out to verify the feasibility and correctness of the simulation. These results show that oil level, rotating speed, and flight attitude have a great influence on splash lubrication performance.

scholarly journals Sensitivity Analysis of Fuel Injection Characteristics of GDI Injector to Injector Nozzle Diameter

Energies ◽  
2019 ◽  
Vol 12 (3) ◽  
pp. 434 ◽  
Author(s):  
Xinhai Li ◽  
Yong Cheng ◽  
Shaobo Ji ◽  
Xue Yang ◽  
Lu Wang
Keyword(s):  
Cfd Simulation ◽  
Fuel Injection ◽  
Injection Pressure ◽  
Nozzle Diameter ◽  
Gasoline Direct Injection ◽  
Small Range ◽  
Fuel Mass ◽  
Single Hole ◽  
Injector Nozzle ◽  
The Difference

The accuracy of a nozzle diameter directly affects the difference of the injection characteristics between the holes and productions of a GDI (gasoline direct injection) injector. In order to reduce the difference and guarantee uniform injection characteristics, this paper carried out a CFD simulation of the effect of nozzle diameter which fluctuated in a small range on single-cycle fuel mass. The sensitivity of the fuel injection quantity to the injector nozzle diameter was obtained. The results showed that the liquid phase ratio at the nozzle outlet decreased and the velocity of the outlet increased with the increase of the nozzle diameter. When fluctuating in a small range of nozzle diameters, the sensitivity of the single-hole fuel mass to the nozzle diameter remained constant. The increase of the injection pressure lead to the increase of the sensitivity coefficient of the single-hole fuel mass to the nozzle diameter. The development of cavitation in the nozzle and the deviation of the fuel jet from the axis were aggravated with the increase of the injection pressure. However, the fluctuation in a small range of nozzles had little effect on the near-nozzle flow.

Dynamic characteristics of threshold value and extension field selections for vacuum-blowing cleaning system

2021 ◽  
Author(s):  
Yuan Xi ◽  
Yan Dai ◽  
Xi-long Zhang ◽  
Gaohong He
Keyword(s):  
Average Velocity ◽  
Structural Parameters ◽  
Threshold Value ◽  
Structural Parameter ◽  
Extension Field ◽  
Cleaning System ◽  
Simulation Calculation ◽  
Computational Fluid Dynamics Cfd ◽  
Computational Resources ◽  
Grid Computation

To provide theoretical guidelines for threshold value selections on performance characteristics of extension field, the flow characteristic in the vacuum-blowing cleaning system was simulated using the average velocity and pressure of the front inlet surface, and the average velocity of the outlet surface, as indices to evaluate the effect of the extension field’s structural parameters. It is found that the extension field parameters have implications for the simulation calculation, and that each parameter has a corresponding threshold. If the structural parameter is greater than the corresponding threshold, the calculation result is not affected, and the threshold values are analyzed by using computational fluid dynamics (CFD). The dimensions of the front, back, left, and right extension fields are recommended as follows: lf=lb=ll=lr=210 mm and θf =θb =θl =θr =55 degree. The flow field distribution characteristic does not have a distinct difference with or without the extension field corner. The extension field with a corner can be used if high accuracy is required. However, to reduce the amount of grid computation and shorten the calculation time, the corner extension field model is not recommended. Finally, the simulation results are verified experimentally and can be used to improve the calculation accuracy and reduce the required computational resources.

Antiknock Performance Comparison Analysis of Refuge Chamber Cabin Based on Different Stiffeners

2014 ◽  
Vol 635-637 ◽  
pp. 397-401
Author(s):  
Xiao Yan Gong ◽  
Jun Xu ◽  
Li Zhang ◽  
Wan Ying Jiao
Keyword(s):  
Low Cost ◽  
Simulation Method ◽  
Performance Comparison ◽  
Comparison Analysis ◽  
Coal Mine Gas ◽  
Tnt Equivalent ◽  
Development Costs ◽  
Simulation Calculation ◽  
Safety And Reliability ◽  
Ansys Workbench

In order to improve the safety and reliability, and reduce development costs of the refuge chamber cabin, we combined TNT equivalent substitute with numerical simulation method, used software AUTODYN to carry on simulation calculation and obtain coal mine gas blast law and determine explosion shock loading. On this basis, four different refuge chamber cabin structure geometries based on stiffeners were designed , then the ANSYS Workbench platform software was used to perform dynamic simulation and safety comparative analysis for anti-knock properties of four different stiffeners refuge chambers, we obtained a mine refuge chamber structure with low-cost and good performance, which provided some ideas for mine refuge chamber’s research and development.

Investigation of Air Injection and Cavity Size Within a Circumferential Combustor to Increase G-Load and Residence Time

2017 ◽  
Vol 140 (1) ◽  
Author(s):  
Andrew E. Cottle ◽  
Marc D. Polanka ◽  
Larry P. Goss ◽  
Corey Z. Goss
Keyword(s):  
Air Force ◽  
Fuel Injection ◽  
Combustion Process ◽  
Combustion Stability ◽  
Gravitational Acceleration ◽  
Complete Combustion ◽  
Centrifugal Load ◽  
Image Velocimetry ◽  
Computational Fluid Dynamics Cfd ◽  
Institute Of Technology

A gas turbine combustion process subjected to high levels of centrifugal acceleration has demonstrated the potential for increased flame speeds and shorter residence times. Ultracompact combustors (UCC) invoke the high-g phenomenon by introducing air and fuel into a circumferential cavity which is recessed radially outboard with respect to the primary axial core flow. Upstream air is directed tangentially into the combustion cavity to induce bulk circumferential swirl. Swirl velocities in the cavity produce a centrifugal load on the flow that is typically expressed in terms of gravitational acceleration or g-loading. The Air Force Institute of Technology (AFIT) has developed an experimental facility in which g-loads up to 2000 times the earth’s gravitational field (“2000 g’s”) have been demonstrated. In this study, the flow within the combustion cavity is examined to determine factors and conditions which invoke responses in cavity g-loads. The AFIT experiment was modified to enable optical access into the primary combustion cavity. The techniques of particle image velocimetry (PIV) and particle streak emission velocimetry (PSEV) provided high-fidelity measurements of the velocity fields within the cavity. The experimental data were compared to a set of computational fluid dynamics (CFD) solutions. Improved cavity air and fuel injection schemes were evaluated over a range of air flows and equivalence ratios. Increased combustion stability was attained by providing a uniform distribution of cavity air drivers. Lean cavity equivalence ratios at a high total airflow resulted in higher g-loads and more complete combustion, thereby showing promise for utilization of the UCC as a main combustor.

Numerical Simulation of Combustion Instabilities in a Lean Premixed Combustor With Finite Rate Chemistry

2003 ◽  
Author(s):  
David J. Cook ◽  
Heinz Pitsch ◽  
Norbert Peters
Keyword(s):  
Fuel Injection ◽  
Combustion Model ◽  
Analysis Tool ◽  
Computational Domain ◽  
Combustion Instabilities ◽  
Finite Rate ◽  
Flow Area ◽  
Lean Premixed ◽  
Dissipation Model ◽  
Computational Fluid Dynamics Cfd

Combustion instabilities in lean premixed gas turbine combustors remain a major limitation in decreasing NOx emissions. Computational Fluid Dynamics (CFD) has become an important design and analysis tool that is often used to predict thermoacoustic oscillations caused by these instabilities. Limitations to prediction accuracy are imposed by the choice of chemistry and combustion model. The focus of this study is to compare CFD calculations using Eddy Dissipation and Finite Rate Chemistry models to experimental data reported by Richards and Janus (1997) on the single-injector lean premixed DOE-NETL combustor. The computational domain consists of an annular swirl inlet, fuel injection, a can combustor, a plug for reduced flow area, and an exhaust plenum. The numerical calculations were done using a RANS solver. A 2D axisymmetric-swirl model with RANS turbulence model was employed. The Eddy Dissipation Model has become popular largely because of its robust performance. It is shown that this model does not predict combustion instabilities for the present case. On the other hand, the Finite Rate Chemistry Model is numerically stiff, but is capable of capturing the onset of combustion instabilities.

scholarly journals Application of Computational Fluid Dynamics (CFD) in the Deposition Process and Printability Assessment of 3D Printing Using Rice Paste

Processes ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 68
Author(s):  
Timilehin Martins Oyinloye ◽  
Won Byong Yoon
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
3D Printing ◽  
Deposition Process ◽  
Operating Conditions ◽  
Nozzle Diameter ◽  
Cfd Analysis ◽  
Flow Properties ◽  
Swell Ratio ◽  
Computational Fluid Dynamics Cfd

Computational fluid dynamics (CFD) was utilized to investigate the deposition process and printability of rice paste. The rheological and preliminary printing studies showed that paste formed from rice to water ratio (100:80) is suitable for 3D printing (3DP). Controlling the ambient temperature at C also contributed to improving the printed sample’s structural stability. The viscoelastic simulation indicated that the nozzle diameter influenced the flow properties of the printed material. As the nozzle diameter decreased (1.2 mm to 0.8 mm), the die swell ratio increased (13.7 to 15.15%). The rise in the swell ratio was a result of the increasing pressure gradient at the nozzle exit (5.48 × 106 Pa to 1.53 × 107 Pa). The additive simulation showed that the nozzle diameter affected both the residual stress and overall deformation of the sample. CFD analysis, therefore, demonstrates a significant advantage in optimizing the operating conditions for printing rice paste.

scholarly journals Study on Influencing Factors and Laws of Fuel Injection Consistency of Common Rail Injector

2021 ◽  
Vol 2097 (1) ◽  
pp. 012001
Author(s):  
Ziwei Zhang ◽  
Chunlong Xu
Keyword(s):  
Fuel Injection ◽  
Solenoid Valve ◽  
Hole Diameter ◽  
Operating Conditions ◽  
Nozzle Diameter ◽  
Common Rail ◽  
Valve Lift ◽  
Needle Valve ◽  
Inlet Hole ◽  
Common Rail Injector

Abstract In order to study the influence of parameters of common rail injector internal components on cycle injection consistency, its simulation model is established by AMESim, and the model is validated by the experimental injection rate data. The effects of solenoid valve spring preload, gag bit lift, fuel discharge hole diameter, fuel inlet hole diameter, needle valve lift, needle valve preload and nozzle diameter on the change of injection quantity under different operating conditions are studied by simulation method, and the impact weight of each parameter on fuel injection consistency is analyzed. The results show that the preload of solenoid valve, fuel discharge hole diameter, oil inlet hole diameter, needle valve lift and nozzle diameter are the main parameters affecting the consistency of cycle injection. The percentages of five parameters influencing on the consistency of cyclic injection are 8.68-16.84%, 11.41-23.68%, 17.2086-37.74%, 12.772-18.34% and 9.69-37.27% respectively.

scholarly journals Numerical Analysis of Fuel Injector Nozzle Geometry - Influence on Liquid Fuel Contraction Coefficient and Reynolds Number

2019 ◽  
Vol 57 (1) ◽  
pp. 23-45
Author(s):  
Lino Kocijel ◽  
Vedran Mrzljak ◽  
Maida Čohodar Husić ◽  
Ahmet Čekić
Keyword(s):  
Reynolds Number ◽  
Liquid Fuel ◽  
Fuel Injection ◽  
Injection Rate ◽  
Nozzle Diameter ◽  
Nozzle Geometry ◽  
Fuel Injector ◽  
Contraction Coefficient ◽  
Nozzle Length ◽  
Injector Nozzle

This paper investigates the influence of the fuel injector nozzle geometry on the liquid fuel contraction coefficient and Reynolds number. The main three fuel injector nozzle geometry parameters: nozzle diameter (d), nozzle length (l) and nozzle inlet radius (r) have a strong influence on the liquid fuel contraction coefficient and Reynolds number. The variation of the nozzle geometry variables at different liquid fuel pressures, temperatures and injection rates was analyzed. The liquid fuel contraction coefficient and Reynolds number increase with an increase in the nozzle diameter, regardless of the fuel injection rate. An increase in the r/d ratio causes an increase in the fuel contraction coefficient, but the increase is not significant after r/d = 0.1. A nozzle length increase causes a decrease in the fuel contraction coefficient. Increase in the nozzle length of 0.5 mm causes an approximately similar decrease in the contraction coefficient at any fuel pressure and any nozzle length. Fuel injectors should operate with minimal possible nozzle lengths in order to obtain higher fuel contraction coefficients.

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