Fluid Dynamics & Materials Processing |
DOI: 10.32604/fdmp.2022.019768
ARTICLE
An Analysis of the Factors Influencing Cavitation in the Cylinder Liner of a Diesel Engine
1State Key Laboratory of Engine Reliability, Weifang, 261061, China
2Weichai Power Co., Ltd., Weifang, 261061, China
3State Key Laboratory of Engines, Tianjin University, Tianjin, 300350, China
*Corresponding Author: Shunshun Qin. Email: qinss@weichai.com
Received: 13 October 2021; Accepted: 22 February 2022
Abstract: Avoiding cavitation inside the water jacket is one of the most important issues regarding the proper design of a diesel engine’s cylinder liner. Using CFD simulations conducted in the frame of a mixture multiphase approach, a moving grid technology and near-wall cavitation model, in the present study the factors and fluid-dynamic patterns that influence cavitation are investigated from both macroscopic and mesoscopic perspectives. Several factors are examined, namely: wall vibration, water jacket width, initial cavitation bubble radius, coolant temperature, and number of bubbles. The results show that reducing the cylinder liner vibration intensity can significantly weaken the cavitation. Similarly, increasing the water jacket width is instrumental in avoiding cavitation. Increasing the coolant temperature reduces the microjet velocity related to bubble collapse, while increasing the number of bubbles produces a much larger water hammer pressure that can cause more damage to the cylinder liner.
Keywords: Cavitation; cavitation dynamics; diesel engine; two-phase flow; water hammer
Nomenclature
Term | Interpretation |
| Time |
| Mixture density |
| Mass-averaged velocity |
| Pressure gradient acting on a unit volume of fluid |
| Mixture viscosity |
| Acceleration due to gravity |
| Body force |
| Volume fraction of phase h |
| Density of phase h |
| Drift velocity of phase h |
| Velocity of phase h |
| Density of liquid phase |
| Turbulent kinetic energy |
ε | Turbulent dissipation rate |
xi | Cartesian coordinate system component in the i direction |
xj | Cartesian coordinate system component in the j direction |
ui | Velocity in the i direction |
µeff | Effective dynamic viscosity |
G | Turbulent kinetic energy generation due to the mean velocity gradient |
YM | Contribution of the compressible turbulence fluctuating dilatation to the overall dissipation rate |
Rε | Term to fix the penultimate term |
C1ε | Constant |
C2ε | Constant |
C |