• Journal of Ocean Engineering and Technology
• /
• v.25 no.5
• /
• pp.21-26
• /
• 2011

Seawater lift pump systems are responsible for maintaining open canal levels to provide the suction flow of circulating water pumps at the set point. The objective of this paper is to design a 2-stage mixed flow pump (for seawater lifting), investigate the new impeller modeling method, and performance improvements of the impeller by using a commercial CFD code. The rotating speed of the impeller is 1,750 rpm with a flow rate of 2,700 m3/h. A finite volume method with a structured mesh and realized k-${\varepsilon}$ turbulent model is used to guarantee a more accurate prediction of turbulent flow in the pump impeller. The performance variables such as the static head, brake horsepower, and efficiency of the mixed flow pump are compared based on changes in the impeller blade shape.

• 유체기계공업학회:학술대회논문집
• /
• 2001.11a
• /
• pp.258-263
• /
• 2001

A fuel pump for a turbopump system has been designed under an international co-work program. The liquid methane fuel pump has an inducer, in front of centrifugal impeller blades, to improve cavitation performance. The three dimensional viscous flow in the fuel pump was investigated through numerical computation. An arrangement of the inducer and impeller has yielded a strong interaction between inducer and impeller blades. The performance of the pump was evaluated from the calculated results. A parametric study was performed for various design variables, and it could oner a database for design parameters to design a fuel pump. A modified design of a fuel pump was proposed by KIMM to improve pump performance.

• Transactions of The Korea Fluid Power Systems Society
• /
• v.8 no.1
• /
• pp.10-18
• /
• 2011

In the beginning of this study, pressure in a cylinder and flow rate from a cylinder of a rotating-cam and fixed-cylinder type radial piston pump are investigated through numerical simulations, so that the simulation results might be utilized as basements for examining physical phenomena occurring in the pump assembly. Then, for supplying basic knowledge on pump design, pressure, flow and leakage characteristics of the pump assembly under the variations of major design parameters are investigated through numerical simulations. At the end, key design parameters influencing upon volumetric efficiency of the pump are listed.

• The KSFM Journal of Fluid Machinery
• /
• v.5 no.3 s.16
• /
• pp.33-39
• /
• 2002

The head-capacity corves for pumps developed by the pump manufacturer are based on tests of a single pump operating in a semi-infinite pool with no nearby walls or floors and with no stray currents. Hence, flow into the pump suction is symmetrical with no vortices or swirling. Pump station designers rely on these curves to define the operating conditions for the pump selected. However, various constraints such as size, cost, and limitations on storage time require walls, floors, and pump intakes to be close proximity to each other. From this background, the authors are carrying out a systematic study on the flow characteristics of intakes within a sump found in pump stations. Model pump intake basin is designed and PIV is adopted as a measuring tool to capture the instantaneous flow patterns. Special attention is paid to investigate the flow patterns near the free surface, side-wall, and back-wall due to different clearances from back-wall to vortical intake pipe. Moreover, the locations and patterns of the various types of vortices that were found in the examinations are discussed.

• The KSFM Journal of Fluid Machinery
• /
• v.14 no.5
• /
• pp.18-23
• /
• 2011

A CFD analysis method is developed and applied for investigating the gas flow and the byproduct particle trajectory in Roots type vacuum pump. The internal fluid flow and thermal fields between the rotors and the housing of vacuum pump are analyzed by using the dynamic mesh, the numerical methods for unsteady 2-D Navier-Stokes equation and the standard k-$\varepsilon$ turbulence model of the Fluent code. Coupled with the flow simulation results, the particle trajectory of the byproduct flowing into the pump with gas stream is analyzed by using discrete phase modeling technique. The CFD analysis results show the pressure, the velocity and the temperature distributions in pump change abruptly due to the rotation of rotors, and back flows are produced due to the strong reverse pressure gradients at rotor/rotor and rotor/housing clearances. The predicted byproduct particle trajectory results also show the particles impinge on the clearance surfaces between the housing and the rotor of pump and then may form the deposit layer causing the failure of pump.

• Proceedings of the KSME Conference
• /
• 2001.11b
• /
• pp.563-569
• /
• 2001

The head-capacity curves for pumps developed by the pump manufacturer are based on tests of a single pump operating in a semi-infinite pool with no nearby walls or floors and no stray currents, Hence, flow into the pump suction is symmetrical with no vortices or swirling. Pump station designers rely on these curves to define the operating conditions for the pump selected. But various constraints such as size, cost, and limitations on storage time require walls, floors, and pump intakes to be close proximity to each other. From this background, the authors are carrying out a systematic study on the flow characteristics of intakes within a sump found in pump stations. Model pump intake basin is designed and PIV is adopted as a measuring tool to capture the instantaneous flow patterns. Special attention is paid to investigate the flow patterns near the free surface, side-wall and back-wall due to different clearances from back-wall to vertical in take pipe. Moreover, the locations and vorticities of the various types of vortices that were found in the examinations are discussed.

• The KSFM Journal of Fluid Machinery
• /
• v.11 no.5
• /
• pp.7-14
• /
• 2008

Open channel type regenerative pump has been used in various industrial fields. It generates high pressure with low flow rate. However, it has low efficiency because of its complex flow pattern, We studied performance experiments and 3D numerical flow analysis of a regenerative pump. Through the numerical analysis, we could get the internal flow pattern and profile of a regenerative pump. Also, we examined leakage flow effects due to the gap between casing and impeller and stripper clearance. For the numerical analysis verification, we performed experiments and they had similar tendency at the design point.

• 유체기계공업학회:학술대회논문집
• /
• 2001.11a
• /
• pp.216-220
• /
• 2001

Flow analysis was carried out for two vertical pumps. The geometrical difference of two pumps is the adoption of vaned diffuser. Full pump models were used to simulate the velocity fields of the pumps. Pump head and velocity field were compared to obtain the features of diffuser flow. It was shown that the discontinuity of head curve was predicted and reverse flow could be generated at impeller exit even in the rated flow condition.

• International Journal of Fluid Machinery and Systems
• /
• v.1 no.1
• /
• pp.101-108
• /
• 2008

The effect of Reynolds number on the performance of a regenerative pump was examined in a low Reynolds number range in experiment. The head of the regenerative pump increased at low flow rates and decreased at high flow rates as the Reynolds number decreased. The computation of the internal flow was made to clarify the cause of the Reynolds number effect. At low flow rates, the head is decreased with increasing the Reynolds number due to the decrease of the shear force exerted by the impeller caused by the increase of leakage and hence local flow rate. At higher flow rates, the head is increased with increasing the Reynolds number with decreased loss at the inlet and outlet as well as the decreased shear stress on the casing wall.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 1997.04a
• /
• pp.533-539
• /
• 1997

Pressure ripple of hydraulic vane pump results form flow ripple due to pump geometry and reverse flow through the discharge port due to compressibility of fluid and result in vibration and noise of connected hydraulic elements. In a ba;anced type vane pump, cam ring curve is important factor to influence the flow ripple. Therefore, to reduce the now ripple, it has been required that optimal selection of seal region by proper design of cam ring and each port position, and notches for preventing the excessive reverse flow. This paper has been performed analytical study of compression characteristics with major design parameter in side plate and cam ring, and examined into the role of notch and radius reduction ratio.