Research on sealing characteristics of annular power cylinder based on twin-rotor piston engine

2021 ◽  
pp. 095440622110214
Author(s):  
Dibo Pan ◽  
Haijun Xu ◽  
Bolong Liu ◽  
Congnan Yang
Keyword(s):  
Compression Ratio ◽  
Simulation Analysis ◽  
Piston Engine ◽  
Leakage Model ◽  
Gas Leakage ◽  
Power Cylinder ◽  
Sealing Performance ◽  
Piston Seal ◽  
Realization Process ◽  
Twin Rotor

The sealing characteristics of an annular power cylinder based on the Twin-rotor piston engine are studied, which provides a theoretical foundation for the sealing design of a new high-power density piston engine. In this paper, the basis thermodynamic realization process of an annular power cylinder is presented. The Runge Kutta equation is used to establish the coupled leakage model of adjacent working chambers under annular piston seal. And the sealing performance of the annular power cylinder is analyzed in detail. Moreover, the influence of rotor speed and compression ratio on the sealing characteristics and leakage is studied. Finally, some tests are carried out to verify the sealing principle and simulation results, which verifies the theoretical basis of simulation analysis. Results show that there are double pressure peaks in the leakage chamber between two working chambers, which is beneficial to reduce the leakage rate. Besides, increasing the speed and decreasing the compression ratio can help to reduce gas leakage. Furthermore, the effects of speed variation on the leakage are only significant when rotating at low speed. Changing the compression ratio has a greater effect on the slope of the leakage curve at a low compression ratio, and the lower the compression ratio, the better the sealing effect.

The Construction and Realization Process of the Virtual Manufacturing Technology in Package Design

2012 ◽  
Vol 271-272 ◽  
pp. 539-543
Author(s):  
Shou Liang Lai
Keyword(s):  
Data Analysis ◽  
Simulation Analysis ◽  
Virtual Manufacturing ◽  
Virtual Design ◽  
Package Design ◽  
Design And Manufacturing ◽  
External Software ◽  
Physical Attributes ◽  
Realization Process ◽  
Design And Manufacture

On the basis of mastering the general virtual design and manufacture, we combined with the data analysis of packing to construct the virtual package design and manufacturing, and the models we need can be build in external software, then we import these and would realize the interaction by Virtools. The interaction and simulation facilitate the validation and data modification of package design and manufacture feasible, and the precision of models, interactive space and relationship, simulation analysis and the key physical attributes of package design and manufacturing are the focused factors.

Effects of Scatter in Bolt Preload of Pipe Flange Connections With Gaskets on Sealing Performance

2003 ◽  
Author(s):  
Toshiyuki Sawa ◽  
Mitsuhiro Matsumoto ◽  
Satoshi Nagata
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Internal Pressure ◽  
Control Method ◽  
Torque Control ◽  
Stress Distributions ◽  
Flange Connection ◽  
Gas Leakage ◽  
Bolt Preload ◽  
Sealing Performance

It has been well known that a scatter in axial bolt forces of pipe flange connections tightened by the torque control method is substantial. It is necessary for evaluating the sealing performance of the pipe flange connections with the gaskets subjected to intemal pressure to know the contact gasket stress distributions due to the scatter of the axial bolt forces in the connections tightened by the torque control method. This paper deals with the leakage of the pipe flange connections with a spiral wound gasket and that with a compressed sheet gasket tightened by the torque control method. The scatter in the axial bolt forces was measured in the experiments. The contact gasket stress distributions at the interfaces of the pipe flange connections with the gaskets were calculated under the measured axial bolt forces by using elasto-plastic finite element method (FEM) taking into account hysteresis and non-linearity in the stress-strain curves of the gaskets. The effects of the scatter in the axial bolt forces tightened by the torque control method on the gas leakage were also examined by using the actual pipe flange connections. As the result, a difference in an amount of gas leakage measured was found to be substantial between our study and PVRC procedure. By using the calculated contact gasket stress distributions under the internal pressure and the results of the leakage tests, the sealing performance was evaluated. It is found that the sealing performance is worse in the actual pipe flange connection than that evaluated by PVRC procedure.

Structural Modal Analysis of a New Twin-Rotor Piston Engine

2013 ◽  
Vol 390 ◽  
pp. 256-260 ◽  
Author(s):  
Qiang Xie ◽  
Cun Yun Pan ◽  
Hu Chen ◽  
Zheng Zhou Zhang ◽  
Lei Zhang
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Natural Vibration ◽  
Structural Parameters ◽  
Vibration Reduction ◽  
Modal Parameters ◽  
Analysis Software ◽  
Piston Engine ◽  
Radiation Noise ◽  
Twin Rotor

With the finite analysis software ANSYS, the key parts and the whole structure of a new twin-rotor piston engine is analyzed, and then the structural modal parameters are obtained by using finite element method in the cases of free modality. Furthermore, the natural vibration characteristics of the twin-rotor piston engine are analyzed, as well as the influence of structural parameters on vibration transfer and radiation noise. The research is expected to lay a foundation for the vibration reduction design of the twin-rotor piston engine.

CNG Car Engine Compression Ratio Optimization and Knock Simulation Analysis

2013 ◽  
Vol 341-342 ◽  
pp. 360-365
Author(s):  
Yan Qin ◽  
Yu Liu ◽  
Yuan Zhi Feng ◽  
Guang Yang Liu ◽  
Guo Dong Feng
Keyword(s):  
Compression Ratio ◽  
Simulation Analysis ◽  
Pressure Rise ◽  
Maximum Temperature ◽  
Cylinder Pressure ◽  
Full Load ◽  
Cng Engine ◽  
Set Up ◽  
Ratio Optimization

We set up one cylinder of CNG engine by using GT-Power software and the compression ratio and the knock are studied. The conclusions are as follows: when the compression ratio increases, the rate of pressure rise of acute burning period increases; The maximum cylinder pressure increases; The maximum temperature decreased slightly and after burning period the temperature increases; The critical knocking compression ratio appears at the full load of 4000rpm conditions; If we only consider it knocking or not, the engine compression ratios can change from 10 to 11.

Stress Analysis and the Sealing Performance Evaluation of Pipe Flange Connections With Gaskets Subjected to Internal Pressure and External Bending Moment: Effects of Scatter in Bolt Preload

2004 ◽  
Author(s):  
Toshiyuki Sawa ◽  
Wataru Maezaki ◽  
Satoshi Nagata
Keyword(s):  
Finite Element Method ◽  
Internal Pressure ◽  
Control Method ◽  
Bending Moment ◽  
Torque Control ◽  
Stress Distributions ◽  
Gas Leakage ◽  
Bolt Preload ◽  
Sealing Performance ◽  
Spiral Wound

It has been well known that a scatter in axial bolt forces of pipe flange connections tightened by the torque control method is substantial. It is necessary for evaluating the sealing performance of the pipe flange connections with the gaskets subjected to internal pressure and external bending moment to know the contact gasket stress distributions due to the scatter of the axial bolt forces in the connections tightened by the torque control method. This paper deals with the leakage of the pipe flange connections with a spiral wound gasket subjected to internal pressure and external bending moment tightened by the torque control method. The scattered axial bolt forces were measured in the experiments. The contact gasket stress distributions at the interfaces between pipe flanges and the gasket were calculated under the measured axial bolt force by using elasto-plastic finite element method (FEM) taking into account hysteresis and non-linearity in the stress-strain curves of spiral wound gasket. The effects of the scatter in the axial bolt forces tightened by the torque control method on the gas leakage were also examined by using the actual pipe flange connections under internal pressure and external bending moment. By using the calculated contact stress distributions and the results of the leakage tests, the sealing performance was evaluated. It is found that the sealing performance is worse in the actual pipe flange connection than that evaluated by PVRC procedure.

Stress Analysis and Sealing Performance Evaluation of Bolted Pipe Flange Connections With Smaller and Larger Nominal Diameter Under Repeated Temperature Changes

2014 ◽  
Author(s):  
Yuya Omiya ◽  
Toshiyuki Sawa
Keyword(s):  
Internal Pressure ◽  
Thermal Condition ◽  
Power Plants ◽  
Thermal Exposure ◽  
Flange Connection ◽  
Gas Leakage ◽  
Nominal Diameter ◽  
Other Hand ◽  
Sealing Performance ◽  
Helium Gas

Pipe flange connections with gaskets in chemical plants, electric power plants and other industrial plants are usually exposed to elevated internal pressure with cyclic thermal condition. It is important to investigate the sealing performance of pipe connections under long term severe thermal exposure swings to ensure operational safety. In this study, the effects of cyclic thermal conditions on the sealing performance and mechanical characteristics in larger and smaller nominal diameter of pipe flange connection are examined using FEM calculations. Helium gas leakage is predicted using the contact gasket stress obtained from the FEM results. On other hand, the leakage tests using the smaller nominal diameter of pipe flange connection were conducted to measure the amount of helium gas leakage and to compare with the predicted amount of gas leakage. As the results, the contact gasket stress distributions were changed dramatically under cyclic thermal condition and elevated internal pressure. In the pipe flange connections with smaller nominal diameter, the contact gasket stress was the smallest in the restart condition. On other hand, the minimum contact gasket stress in the pipe flange connection with larger nominal diameter was depending on the materials of connection. In the pipe flange connection with larger nominal diameter, the contact gasket stress distributed and changed in the radial direction due to the flange rotation. A fairly good agreement was found between the experimental leakage result and predicted leakage results.

scholarly journals An investigation of a hypocycloid mechanism based twin-rotor piston engine

2014 ◽  
Vol 229 (1) ◽  
pp. 106-115
Author(s):  
Xiaojun Xu ◽  
Haijun Xu ◽  
Hao Deng ◽  
Fengshou Gu ◽  
Chris Talbot
Keyword(s):  
Lightweight Design ◽  
Dynamical Analysis ◽  
Design Parameters ◽  
Uniform Motion ◽  
Force Transmission ◽  
Piston Engine ◽  
Critical System ◽  
Piston Velocity ◽  
Angular Velocities ◽  
Twin Rotor

A unique mechanism is investigated in this paper to show the working principles of a novel hypocycloid twin-rotor piston engine (HTRPE), which provides the basis for the structural design, kinematic and dynamical analysis necessary to realize the engine. As a critical system for the HTRPE, the differential velocity mechanism is examined first by decomposing it into two non-uniform motion mechanisms and one hypocycloid mechanism, which allows an evaluation of different options of design parameters. Then analytical expressions are derived to calculate the rotor angular velocities and the relative angular velocities of pairs of rotors for a detailed performance analysis. Based on the results of this analysis a prototype HTRPE is proposed and benchmarked with both a conventional reciprocating and a Wankel engine. It is shown that the new engine outperforms the other two engines in key engine features including combustion gas force transmission, volumetric change of working chambers, power frequency, piston velocity and displacement, demonstrating that HTRPE is very promising as a more energy efficient engine due to its high compactness and power density, and consequently lightweight design.

Fuzzy Reliability Optimization Design Method of Flange Based on the Tightness of Bolted Flanged Connections

2010 ◽  
Vol 37-38 ◽  
pp. 501-504
Author(s):  
Zhen Guo Sun ◽  
Bo Qin Gu ◽  
Xing Lu Huang
Keyword(s):  
Probability Theory ◽  
Optimization Design ◽  
Design Method ◽  
Design Parameters ◽  
Reliability Optimization ◽  
Fuzzy Reliability ◽  
Leakage Model ◽  
Sealing Performance ◽  
Random Probability ◽  
Fuzzy Random

Based on the time-correlated leakage model and fuzzy random probability theory, a formula for calculating fuzzy random reliability of sealing performance of bolted flanged connections was derived. The optimization variables were defined according to the sensitivity analysis of design parameters on fuzzy reliability of sealing performance. A fuzzy reliability optimization design method of flange was investigated, in which both the tightness of bolted flanged connections and the strength of flange were taken into consideration. As an example, an integral welding necked pipe flange was designed according to the optimization design method proposed in this paper. The designed flange not only satisfies the requirements of flange strength and sealing reliability of connections, but also its weight is reduced by 16% compared with that prescribed in the standard.

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