Power Cylinder Scuffing: Mechanisms

2020 ◽  
Author(s):  
Keyword(s):  
Power Cylinder

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.

scholarly journals STUDY OF THE OPTICAL POWER OF NANOPHOTONIC SOFT CONTACT LENSES BASED ON POLY (2- HYDROXYETHYL METHACRYLATE) AND FULLERENE

2014 ◽  
Vol 5 (1) ◽  
Author(s):  
Aleksandra Debeljković Mitrović ◽  
Dragomir Stamenković ◽  
Manuel Conte ◽  
Božica Bojović ◽  
Spomenko Mihajlović
Keyword(s):  
Contact Lens ◽  
Contact Lenses ◽  
Measurement Techniques ◽  
Optical Power ◽  
Soft Contact ◽  
Standard Material ◽  
Soft Contact Lenses ◽  
Soft Contact Lens ◽  
Power Cylinder

In this paper results of comparative study of the optical power of soft contact lenses (SCL) made of standard material for SCL and nanophotonic materials with different measurement techniques used for the final contact lens controllers are presented. Three types of nanophotonic soft contact lenses were made of standard polymacon material (Soleko SP38TM) incorporated with fullerene C60, fullerol C60(OH)24 and fullerene metformin hydroxylate C60(OH)12(OC4N5H10)12. For the purposes of material characterization for potential application as soft contact lenses, the optical properties of the soft contact lenses were measured by Rotlex and Nidek device. With Rotlex device the following optical results were obtained: optical power and map of defects, while with the Nidek device: optical power, cylinder power and cylinder axis. The obtained values of optical power and map of defects showed that the optical power of synthesized nanophotonic soft contact lens is same to the nominal value, while this was not the case for the standard soft contact lens. Also, the quality of the nanophotonic soft contact lens is better than the standard one. Hence, it is possible to synthesize new nanophotonic soft contact lenses of desired optical characteristics, implying possibilities for their application in this field.

Control Characteristics of Fluid Power Cylinder Moving Up and Down

2004 ◽  
Vol 28 (8) ◽  
pp. 1152-1158
Author(s):  
Man-Oh Yum ◽  
Il-Ro Yoon ◽  
Seok-Young Lee
Keyword(s):  
Fluid Power ◽  
Power Cylinder

A Study to Determine Factors That Have Influence on the Propensity of Natural LSPI Occurring in GTDI Engines

2018 ◽  
Author(s):  
Paras Sethi ◽  
Eric Passow ◽  
Kimm Karrip ◽  
Max Maschewske ◽  
Jason Bieneman ◽  
...  
Keyword(s):  
Life Cycle ◽  
Effective Means ◽  
Test Procedure ◽  
Engine Performance ◽  
Test Results ◽  
Performance Targets ◽  
Power Cylinder ◽  
The Many ◽  
Procedure Development ◽  
Vehicle Platform

There are many articles and papers published about the developments in engine downsizing as an effective means in reducing vehicle fuel consumption while improving engine performance. The increase in performance of gasoline turbo charged direct injected (GTDI) engines, in conjunction with diverse vehicle platform performance targets (i.e. towing capability) and higher gear transmissions pushes the engine to operate with higher torques at lower engine speeds. This operating condition has increased the propensity of an abnormal combustion event, known as Low Speed Pre-Ignition (LSPI) or Stochastic Pre-Ignition (SPI). The power cylinder unit (PCU) components exposed to this pre-ignition event can experience failure. The engine manufacturers, as well as MAHLE, continue to ensure engine and PCU component survivability against LSPI by performing life cycle robustness testing. MAHLE’s research of LSPI continues to focus on the robustness of PCU components in the presence of LSPI events, as well as investigating design developments that have the potential to minimize the propensity of LSPI to occur. The test procedure development for evaluating natural LSPI events will be presented. Various test results and parameter sensitivities that were documented during this procedure development, along with the many challenges associated with engine performance repeatability will be discussed. Parameters that were found to influence LSPI propensity, as well as parameters that were found not to influence LSPI propensity will be discussed.

Correlation of Power Cylinder Modeling to Empirical Measurements in a John Deere 6135H 13.5L I-6 Engine

2009 ◽  
Author(s):  
Max Maschewske ◽  
Erich Rabassa ◽  
Kimm Karrip ◽  
Greg Vander Veen ◽  
Randy Lunsford ◽  
...  
Keyword(s):  
Correlation Study ◽  
Oil Consumption ◽  
Power Cylinder ◽  
Development Cycle ◽  
Model Predictions ◽  
Correlation Parameters ◽  
Analytical Tools ◽  
Physical Phenomena ◽  
Land Pressure ◽  
Gas Pressures

Motivated by the need to achieve greater efficiency in the product development cycle, engine manufacturers in the heavy-duty industry are relying more and more on analytical tools to help resolve performance issues, minimize testing costs and reduce time to market. This is particularly the case in the area of power cylinder development, since the physical phenomena occurring within the cylinders are difficult to observe and quantify. However, analytical tools are useful only if they are able to accurately represent the physical systems that they are supposed to simulate. It therefore becomes critical to establish a correlation between model predictions and empirical measurements. To this end, a correlation study was initiated comparing power cylinder analytical modeling results to empirical measurements in a John Deere 6135H 13.5L I-6 engine. The engine test measurements that were carried out included cylinder pressure, piston land pressure, engine blowby, and lube oil consumption. The correlation parameters considered in the study included piston land gas pressures, power cylinder contribution to engine blowby, and lube oil consumption mechanisms.

Sign in / Sign up

Export Citation Format

Share Document