A study on the behavior characteristics of diesel spray by using a high pressure injection system with common rail apparatus

2003 ◽  
Vol 17 (9) ◽  
pp. 1371-1379 ◽  
Author(s):  
Jeong-Kuk Yeom ◽  
Hajime Fujimoto
Keyword(s):  
High Pressure ◽  
Common Rail ◽  
Injection System ◽  
Diesel Spray ◽  
Pressure Injection ◽  
Behavior Characteristics ◽  
High Pressure Injection

A Comprehensive Thermodynamic Approach to Acoustic Cavitation Simulation in High-Pressure Injection Systems by a Conservative Homogeneous Two-Phase Barotropic Flow Model

2005 ◽  
Vol 128 (2) ◽  
pp. 434-445 ◽  
Author(s):  
Andrea E. Catania ◽  
Alessandro Ferrari ◽  
Michele Manno ◽  
Ezio Spessa
Keyword(s):  
High Pressure ◽  
Wave Propagation ◽  
Flow Model ◽  
Acoustic Cavitation ◽  
Injection System ◽  
Pure Liquid ◽  
Two Phase ◽  
Pressure Injection ◽  
Barotropic Flow ◽  
High Pressure Injection

A general conservative numerical model for the simulation of transmission-line unsteady fluid dynamics has been developed and applied to high-pressure injection systems. A comprehensive thermodynamic approach for modeling acoustic cavitation, i.e., cavitation induced by wave propagation, was proposed on the basis of a conservative homogeneous two-phase barotropic flow model of a pure liquid, its vapor, and a gas, both dissolved and undissolved. A physically consistent sound speed equation was set in a closed analytical form of wide application. For the pure-liquid flow simulation outside the cavitation regions, or in the absence of these, temperature variations due to compressibility effects were taken into account, for the first time in injection system simulation, through a thermodynamic relation derived from the energy equation. Nevertheless, in the cavitating regions, an isothermal flow was retained consistently with negligible macroscopic thermal effects due to vaporization or condensation, because of the tiny amounts of liquid involved. A novel implicit, conservative, one-step, symmetrical, and trapezoidal scheme of second-order accuracy was employed to solve the partial differential equations governing the pipe flow. It can also be enhanced at a high-resolution level. The numerical model was applied to wave propagation and cavitation simulation in a high-pressure injection system of the pump-line-nozzle type for light and medium duty vehicles. The system was relevant to model assessment because, at part loads, it presented cavitating flow conditions that can be considered as severe, at least for a diesel injection system. The predicted time histories of pressure at two pipe locations and of injector needle lift were compared to experimental results, substantiating the validity and robustness of the developed conservative model in simulating acoustic cavitation inception and desinence with great accuracy degree. Cavitation transients and the flow discontinuities induced by them were numerically predicted and analyzed.

A Comprehensive Thermodynamic Approach to Acoustic Cavitation Simulation in High-Pressure Injection Systems by a Conservative Homogeneous Barotropic-Flow Model

2003 ◽  
Author(s):  
Andrea E. Catania ◽  
Alessandro Ferrari ◽  
Michele Manno ◽  
Ezio Spessa
Keyword(s):  
High Pressure ◽  
Wave Propagation ◽  
Numerical Model ◽  
Acoustic Cavitation ◽  
Injection System ◽  
Thermodynamic Approach ◽  
Pure Liquid ◽  
Model Assessment ◽  
Pressure Injection ◽  
High Pressure Injection

A general conservative numerical model for simulation of transmission-line unsteady fluid-dynamics has been developed and applied to high-pressure injection systems. A comprehensive thermodynamic approach for modeling acoustic cavitation, i.e. cavitation induced by wave propagation, was proposed on the basis of a homogeneous barotropic mixture model of a pure liquid in equilibrium with its vapor and a gas, both dissolved and undissolved. For the pure liquid flow simulation outside the cavitation regions, or in the absence of these, temperature variations due to compressibility effects were taken into account, for the first time in injection system simulation, through a thermodynamic state equation which was derived from energy considerations. Nevertheless, in the cavitation regions, an isothermal flow was retained which is consistent with negligible thermal effects due to vaporization because of the tiny amounts of liquid involved. A novel implicit, conservative, one step, symmetrical and trapezoidal scheme of the second-order accuracy was applied to solve the hyperbolic partial differential equations governing the pipe flows. It can also be enhanced at a high-resolution level. The numerical model was applied to wave propagation and cavitation simulation in a high-pressure injection system of the pump-line-nozzle type for light and medium duty vehicles. The system was of relevance to the model assessment because it presented severely cavitating flow conditions. The predicted pressure time histories at two pipe locations and injector needle lift were compared to experimental results, substantiating the validity and robustness of the developed conservative model in simulating cavitation inception and desinence with great degree of accuracy. Cavitation transients and the flow discontinuities induced by them were numerically analyzed and discussed.

Analysis of PWR RPV lower head SBLOCA scenarios with the failure of high-pressure injection system using MAAP5

2014 ◽  
Vol 77 ◽  
pp. 48-64 ◽  
Author(s):  
Wei Li ◽  
Xiaoli Wu ◽  
Yapei Zhang ◽  
Deyou Ma ◽  
Yongzheng Chen ◽  
...  
Keyword(s):  
High Pressure ◽  
Injection System ◽  
Pressure Injection ◽  
Lower Head ◽  
High Pressure Injection

scholarly journals Exhaust Gas Characteristics According to the Injection Conditions in Diesel and DME Engines

2019 ◽  
Vol 9 (4) ◽  
pp. 647 ◽  
Author(s):  
Seamoon Yang ◽  
Changhee Lee
Keyword(s):  
High Pressure ◽  
Injection Pressure ◽  
Common Rail ◽  
Nox Emissions ◽  
Exhaust Gas ◽  
Pilot Injection ◽  
Compression Ignition ◽  
Compression Ignition Engine ◽  
Pressure Injection ◽  
High Pressure Injection

In this paper, the effect of high-pressure injection pressure on particulate matter (PM) and nitrogen oxide (NOx) emissions is discussed. Many studies have been conducted by active researchers on high-pressure engines; however, the problem of reducing PM and NOx emissions is still not solved. Therefore, in the existing diesel (compression ignition) engines, the common rail high-pressure injection system has limitations in reducing PM and NOx emissions. Accordingly, to solve the exhaust gas emission problem of a compression ignition engine, a compression ignition engine using an alternative fuel is discussed. This study was conducted to optimize the dimethyl ether (DME) engine system, which can satisfy the emission gas exhaust requirements that cannot be satisfied by the current common rail diesel compression ignition engine in terms of efficiency and exhaust gas using DME common rail compression ignition engine. Based on the results of this study on diesel and DME engines under common rail conditions, the changes in engine performance and emission characteristics of exhaust gases with respect to the injection pressure and injection rate were examined. The emission characteristics of NOx, hydrocarbons, and carbon monoxide (CO) emissions were affected by the injection pressure of pilot injection. Under these conditions, the exhaust gas characteristics were optimized when the pilot injection period and needle lift were varied.

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