High Precision New Diesel Injector Control Valve F00RJ02056 Valve Assembly for Fuel Injector Engine Spare Parts

Numerical Simulation and Experimental Verification of Flow Characteristics within Valve Assemblies

Abstract
Valve assemblies are key components in hydraulic and fuel injection systems. Their internal flow characteristics directly impact the system's pressure stability, response speed, and energy efficiency. This paper systematically investigates the flow mechanisms within valve assemblies by combining numerical simulation with experimental verification, and proposes structural optimization strategies.

1 Introduction
During valve assembly operation, fluid flows through the valve core, valve seat, and micro-gap channels. The flow state often exhibits complex three-dimensional transient characteristics, such as vortices, cavitation, and turbulence. Traditional theoretical analysis struggles to fully reveal these nonlinear effects. Therefore, it is necessary to utilize numerical simulation methods, combined with experimental verification, to obtain more reliable research results.

2 Numerical Simulation Methods
Computational fluid dynamics (CFD) is used to model the flow field within the valve assembly. The geometric model includes the valve body, valve core, and flow channel, and the fluid boundary conditions are set based on the actual operating pressure and flow rate. Dynamic meshing is used to simulate valve core motion, and turbulence models (such as k-ε or LES) are employed to capture vortex structures. The simulation results reveal the velocity distribution, pressure gradient, and evolution of the cavitation region in the flow field. The study found that the local contraction effect at the edge of the valve port causes a sudden drop in pressure, which is the main cause of cavitation.

3 Experimental Verification
In order to verify the accuracy of the numerical model, a valve assembly flow characteristic test platform was built. The high-pressure oil source and transparent observation window were used to achieve visual observation of the fluid flow process. At the same time, laser particle velocimetry (PIV) and high-speed camera technology were used to measure the flow field in the valve port area, and dynamic signals were collected by pressure sensors. The experimental results showed that the flow velocity distribution and cavitation trend predicted by the numerical simulation were highly consistent with the measured results, verifying the reliability of the simulation model.

4 Results and Discussion
The combined numerical and experimental results show that:

(1) The valve core opening has a significant impact on the flow characteristics. At a small opening, the local flow velocity is too high, which can easily lead to uneven flow;

(2) The valve seat geometric parameters determine the cavitation intensity. Optimizing the valve port chamfer and transition curve can effectively inhibit bubble formation;

(3) The clearance between the valve core and the valve body has a significant impact on leakage and energy loss. A balance needs to be achieved between sealing and flow efficiency.

5 Conclusions
This method, combined with numerical simulation and experimental verification, effectively reveals the flow mechanisms within valve assemblies. These results not only provide a basis for valve assembly structural optimization but also lay a theoretical foundation for the efficient and stable operation of hydraulic and fuel injection systems. Future work could further incorporate multi-physics coupling models to explore the flow behavior of valve assemblies under the combined effects of temperature and cavitation.