Interrelation Between Mechanical Energy Supply and Flow Rate in Practical Operation of Centrifugal Pump

2004 ◽  
Author(s):  
Takaharu Tanaka
Keyword(s):  
Energy Supply ◽  
Mechanical Energy ◽  
Rotating Flow ◽  
Centripetal Force ◽  
Impeller Blade ◽  
Flow Passage ◽  
Practical Operation ◽  
Pump Head ◽  
Fluid Particles ◽  
Remaining Time

Pump head plays an external centripetal force and balanced with imaginary centrifugal force. Fluid particles circularly forward tangential movement in the direction tangent increases with the fluid particles remaining time increase in the rotating flow passage. And fluid particles circularly forward tangential movement in the direction tangent is caused by the imaginary mechanical force perpendicular to rotational radius. Therefore, mechanical energy supply is proportional to fluid particles remaining time in the rotating flow passage of impeller blade to cause the circularly forward tangential movement.

Fluid Particle’s Rotational Speed at the Trailing Edge of Impeller Outlet of Centrifugal Pump

2003 ◽  
Author(s):  
Takaharu Tanaka
Keyword(s):  
Centrifugal Force ◽  
Flow Rate ◽  
Mechanical Energy ◽  
Fluid Particle ◽  
Rotating Flow ◽  
Centripetal Force ◽  
Impeller Blade ◽  
Flow Passage ◽  
Impeller Outlet ◽  
Pump Head

Mechanical force caused by mechanical energy acts real and imaginary forces on impeller blade. Therefore, impeller blade moves in the direction of real force, straightly forward in the direction of tangent perpendicular to rotational radius and the direction of imaginary force, circularly forward in the direction of tangent perpendicular to rotational radius. Former real movement causes on fluid particle radial outward movement, resulting to flow rate Q. Latter imaginary movement causes on fluid particle a rotational motion under the external centripetal and imaginary centrifugal force, resulting to pump head. Pump head is equivalent to external centripetal force and balanced with imaginary centrifugal force in the rotating flow passage.

An Investigation on Velocity Triangle Applied to Fluid Particle at Rotating Flow Passage of Impeller Blade in Centrifugal Pump

Volume 1 ◽  
2004 ◽  
Author(s):  
Takaharu Tanaka ◽  
Chao Liu
Keyword(s):  
Flow Rate ◽  
Tangential Velocity ◽  
Maximum Flow ◽  
Maximum Flow Rate ◽  
Rotating Flow ◽  
Impeller Blade ◽  
Flow Passage ◽  
Rotating Speed ◽  
Velocity Triangle ◽  
Fluid Particles

Although impeller blades rotational speed is kept constant for the change in flow rate, fluid particles rotating speed varies by the flow rate. Fluid particles circularly forward tangential velocity becomes zero at the maximum flow rate and the maximum at the flow rate zero. While fluid particles fundamental straightly forward tangential velocity normal to rotational radius becomes the maximum at the maximum flow rate and zero at flow rate zero.

Interrelation Between Fluid Particles Rotational Motion in Rotating Flow Passage of Centrifugal Pump and Overall Efficiency

Volume 3 ◽  
2004 ◽  
Author(s):  
Takaharu Tanaka ◽  
Chao Liu
Keyword(s):  
Centrifugal Pump ◽  
Rotational Motion ◽  
Rotating Flow ◽  
Energy Losses ◽  
Trailing Edge ◽  
Flow Passage ◽  
Impeller Outlet ◽  
Overall Efficiency ◽  
Fluid Particles ◽  
The Way

Main purpose of investigation has been put on the hydraulic energy losses caused in the rotating flow passage of centrifugal pump. Result of discussion shows that fundamental poor efficiency is brought by the fluid particles poor rotational motion at the trailing edge of impeller outlet, including the rotational motion caused in the flow passage between impeller blades rather than the hydraulic energy losses caused in the rotating flow passage. Therefore, our main purpose of investigation has to be put on the way rather to the fluid particles rotational motion caused at the trailing edge of impeller outlet and that caused between impeller blades.

Fluid Particles Straightly Forward and Circularly Forward Movements in the Direction of Tangent at Trailing Edge of Impeller Outlet in Centrifugal Turbomachinery

2003 ◽  
Author(s):  
Takaharu Tanaka
Keyword(s):  
Centrifugal Force ◽  
Flow Rate ◽  
Rotational Motion ◽  
Mechanical Energy ◽  
Centripetal Force ◽  
Impeller Outlet ◽  
Water Turbine ◽  
Fluid Particles ◽  
Centripetal Forces ◽  
Acting Force

Flow rate, which is caused in the direction radial outward in pump and radial inward in water turbine, is caused by the fluid particles straightly forward tangential movement in the direction of acting force perpendicular to impeller blades rotational radius. Impeller blades rotational motion is caused under the radial balance of centrifugal and centripetal forces. Centrifugal force is caused by the transferred energy from mechanical to hydraulic energy in pump and from hydraulic to mechanical energy in water turbine. Centripetal force is equivalent to discharge head in pump and equivalent to suction head in water turbine.

Fundamental Energy Transfer Mechanism of Turbomachinery

2002 ◽  
Author(s):  
Takaharu Tanaka
Keyword(s):  
Energy Transfer ◽  
Centrifugal Force ◽  
Mechanical Energy ◽  
Rotational Flow ◽  
Energy Transfer Mechanism ◽  
Centrifugal Pumps ◽  
Impeller Blade ◽  
Water Turbine ◽  
Fluid Particles ◽  
Water Turbines

Fundamental mechanisms of energy transfer, which is caused between impeller blade and fluid particles in centrifugal pumps and water turbines, are discussed together with as a turbomachinery under same theoretical basement. This leads to the result that the fluid flow which directs radial outward in pump and that radial inward in water turbine are neither caused by centrifugal force nor centripetal force, but caused by tangential forward force, which acts on the impeller blade in the direction perpendicular to rotational radius. Hydraulic energies of fluid particles transferred from mechanical to hydraulic energy in pump and that to be transferred from hydraulic to mechanical energy in water turbine appear as centrifugal force FHCF in rotational flow passage.

scholarly journals Effects of the Impeller Blade with a Slot Structure on the Centrifugal Pump Performance

Energies ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1628 ◽  
Author(s):  
Hongliang Wang ◽  
Bing Long ◽  
Chuan Wang ◽  
Chen Han ◽  
Linjian Li
Keyword(s):  
Velocity Distribution ◽  
Centrifugal Pump ◽  
Deflection Angle ◽  
Fluid Velocity ◽  
Slot Width ◽  
Front Edge ◽  
Impeller Blade ◽  
Flow Passage ◽  
Pump Performance ◽  
Slot Structure

An impeller blade with a slot structure can affect the velocity distribution in the impeller flow passage of the centrifugal pump, thus affecting the pump’s performance. Various slot structure geometric parameter combinations were tested in this study to explore this relationship: slot position p, slot width b1, slot deflection angle β, and slot depth h with (3–4) levels were selected for each factor on an L16 orthogonal test table. The results show that b1 and h are the major factors influencing pump performance under low and rated flow conditions, while p is the major influencing factor under the large flow condition. The slot structure close to the front edge of the impeller blade can change the low-pressure region of the suction inlet of the impeller flow passage, thus improving the fluid velocity distribution in the impeller. Optimal slot parameter combinations according to the actual machining precision may include a small slot width b1, slot depth h of ¼ b, slot deflection angle β of 45°–60°, and slot position p close to the front edge of the blade at 20–40%.

An Investigation on Real and Imaginary Energy Transfer Mechanism Caused in Rotating Flow Passage of Centrifugal Pump

2005 ◽  
Author(s):  
Takaharu Tanaka ◽  
Chao Liu
Keyword(s):  
Energy Transfer ◽  
Physical Properties ◽  
Centrifugal Pump ◽  
Rotational Motion ◽  
Rotating Flow ◽  
Physical Parameters ◽  
Energy Transfer Mechanism ◽  
Flow Passage ◽  
Different Types ◽  
Force Velocity

Hydraulic energy is constructed from real and imaginary energies. Their acting directions are normal to each other. Their physical properties are quite different. All the physical parameters, such as force, velocity, and acceleration therefore consist of two different type real and imaginary functions. Physically, there are three different types of fluid particles rotational motion: straightly forward non-rotational motion, which is based upon kinetic real physical parameters, circularly forward rotational motion, which is based upon un-kinetic imaginary physical parameters, and their combined rotational motion. Their interrelation is shown in diagram.

scholarly journals The influence of flow passage geometry on the performances of a supercritical CO2 centrifugal compressor

2018 ◽  
Vol 22 (Suppl. 2) ◽  
pp. 409-418 ◽  
Author(s):  
Dong-Bo Shi ◽  
Yu-Qi Wang ◽  
Yong-Hui Xie ◽  
Di Zhang
Keyword(s):  
Centrifugal Compressor ◽  
Supercritical Co2 ◽  
Pressure Ratio ◽  
Leading Edge ◽  
Thermal Design ◽  
Original Design ◽  
Impeller Blade ◽  
Flow Passage ◽  
Ansys Cfx ◽  
Design Idea

In this paper, based on the thermodynamic design of the supercritical carbon dioxide (sCO2) centrifugal compressor, the design idea of the flow passage geometries and the method to improve the performance of the sCO2 centrifugal compressor are discussed. With the help of commercial software ANSYS CFX, the influence of the shape of the leading edge and trailing edge is studied, and the elliptical leading edge makes the pressure ratio 10.30% higher and the efficiency 3.95% higher than the square leading edge. By changing the forward-swept angle and backward-swept angle of the leading edge, the effects of aerodynamic swept shape in sCO2 centrifugal compressor are discussed. The effect of the gap between the impeller blade and diffuser blade is discussed, and the 10 mm gap makes the performance best. The pressure ratio is increased by 2.5% compared with the original design, while at the same time the efficiency is slightly improved. In summary, based on thermal design of the sCO2 centrifugal compressor, the effects of different flow geometries are analyzed in detail.

Sign in / Sign up

Export Citation Format

Share Document