Impinging Performance of High-Pressure Water Jets Emitting from Different Nozzle Orifice Shapes

Abstract

The impinging pressure of a water jet is a key factor in engineering applications, and the jet shape has a great influence on this pressure. In this paper, five different nozzle shapes were designed, and impacting tests were conducted based on a self-designed experimental platform using a PVDF piezoelectric film sensor and a high-speed camera to record the impacting data. Additionally, the computational fluid dynamics (CFD) method was also applied to study the velocity distribution. The results show that the pressure profiles of different water jet shapes impacting onto a solid surface present a consistent pattern, namely, an initial transient and enormous peak pressure and then a longer and smaller stagnation pressure. Although the stagnation pressure in this paper is not sufficiently obvious, the peak pressures of the five water jet shapes are much different from one another. Under the same inlet pressure, the peak pressure of the circular water jet is the largest, and those of the square, triangular, cross-shaped, and elliptical water jets decrease in turn. The flowing regimes captured by the high-speed camera together with the CFD simulation results indicate that the discrepancy in the peak pressure may be a combined action of the liquid velocities and jet head shapes.

A new calculation formula to describe the dynamic pressure of water jet peening with elliptical nozzle for high-efficiency treatment

“…This verifies the accuracy and rationality of the proposed formula.

Figure 16.Comparison of impact pressure by the proposed formula and the experiment from Ref. 46,47.

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“…Figure 16 shows the comparison of impact pressure by the proposed formula and the experiment from Ref. 47. It shows that compared with the traditional calculation formula of impact pressure, the impact pressure distribution calculated by the new formula proposed in this article is in better agreement with the value obtained by the test.…”

“…In order to verify the reliability of the newly proposed calculation formula, the predicted impact pressure distribution for the elliptical jet was compared with Refs 46. and 47.…”

“…In order to verify the reliability of the newly proposed calculation formula, the predicted impact pressure distribution for the elliptical jet was compared with Refs 46. and 47. in which the impact pressure was tested based on a self-designed experimental platform using a PVDF piezoelectric film sensor.…”

“…In addition, the literature 47 used an experimental platform to measure the water jet pressure distribution of an elliptical nozzle when the jet inlet velocity is about 100 m/s. The pressure distribution law is similar to that of a traditional circular nozzle.…”