An experimental study of the effect of the projection ratio and throat-aspect ratio on the efficiency and loss coefficient of a water jet pump

Abstract

This study focuses on the influence of dimensionless geometry parameters on the performance and loss coefficient of the throat and diffuser of the water jet pump apparatus. A water jet pump system was designed for a total of nine experimental cases with three different projection ratios and three throat-aspect ratios . The volumetric and pressure ratios - performance parameters are measured at a constant motive pressure and under varying backpressure. The efficiencies of the water jet pump in each configuration were assessed and compared. It was found that increasing 2 or 3 times of projection ratio degrades efficiency about 2% to 5.5%, respectively. Higher projection ratio ( > 1) expands the water jet diameter, which clogs the secondary flow. Hence, the changes in > 3 may have a significant impact on efficiency degradation. Shorter may cause the loss of kinetic energy in the diffuser, while longer reduces momentum transfer on the secondary flow. Moreover, the changes in and influence friction loss coefficient in the throat and diffuser section, and it reduces with increasing of volumetric ratio. It can be concluded that the appropriate value of projection ratio and throat-aspect ratio plays a role in the kinetic energy dissipation. It is also responsible for the location friction process, at a different volumetric ratio. However, the experimental results denoted the best efficiency and loss coefficient was achieved at a low projection ratio ( = 1) and small throat-aspect ratios ( = 5). The best efficiency of the study was about 23.37%.

Su Jet Pompalarinin Performansi Ve Kati-Sivi Karişim Taşimaciliğinda Uygulanmasi

“…Based on the general trend observed in all experimental data, it can be inferred that the efficiency of the pump first increases and then decreases as M increases, with a maximum value in between. This trend is consistent with previous studies, such as Helios and Asvapoositkul (2021), who achieved a maximum WJP efficiency of =0.233 at M=0.87, and Schulz and Fasol (Yapıcı and Aldas, 2013), who obtained the maximum jet pump efficiency value of =0.36 at M=1.4. Yapıcı and Aldas (2013) attributed this trend to the internal structure of flow through the driving and suction lines, which plays a crucial role in the initial increase and subsequent decrease in efficiency with increasing M. The findings of the current study suggest that using a 90 suction line connection to the suction nozzle leads to higher energy losses in the system, ultimately causing a decrease in efficiency.…”

Improvement of the Axial-Jet-Pump Performance using Modified Mixing Chamber Configuration and Inlet Swirling Flow

“…Helios and Asvapoositkul [19] designed a water jet pump apparatus for a total of nine experimental cases with three di erent area ratios and three mixing chambers in order to examine the e ect of geometrical parameters on the performance and loss coe cient of the mixing chamber and di user of the water jet pump. Their results announced the best e ciency was 23.37%, and the low area ratio and the small mixing chamber resulted in the best loss coe cient.…”

Numerical studies for effect of geometrical parameters on water jet pump performance via entropy generation analysis

“…The results can be represented in visual form to analyse the flow structure and reveal the transport mechanisms in the flows of fluid. Various studies have dealt with comparisons and review dealing with the design parameter of the water jet pump [9][10][11][12][13][14].…”