Flow Analysis and Design Suggestions for Regenerative Flow Pumps (Keynote)

2003 ◽  
Author(s):  
Abraham Engeda
Keyword(s):  
Flow Analysis ◽  
Flow Region ◽  
Design Guideline ◽  
Fully Developed Flow ◽  
Analysis And Design ◽  
Vortex Pump ◽  
Developing Region ◽  
The Status ◽  
Regenerative Flow ◽  
Flow Pump

The Regenerative Flow Pump, here referred to as RFP is a turbomachine capable of developing high pressure ratios in a single stage. It is also known with other names such as: • Peripheral pump; • Side channel pump; • Turbine pump; • Drag pump; • Traction pump; • Vortex pump. This paper reviews the status of the RFP and proposes a design guideline, with the aim to improve the performance and efficiency of the RFP. All previous works concentrated on the fully-developed flow region in the RFP and this work expands the consideration to the developing region.

A modified theory for the flow mechanism in a regenerative flow pump

2003 ◽  
Vol 217 (3) ◽  
pp. 311-321 ◽  
Author(s):  
J. W. Song ◽  
A Engeda ◽  
M. K. Chung
Keyword(s):  
Flow Region ◽  
Hydrogen Gas ◽  
Space Vehicles ◽  
Fully Developed Flow ◽  
Vortex Compressor ◽  
Agricultural Industries ◽  
Flow Compressor ◽  
Regenerative Flow ◽  
Modified Theory ◽  
Flow Pump

The regenerative flow pump (RFP) and regenerative flow compressor (RFC) are turbomachines capable of developing high pressure ratios in a single stage. They are also known by other names, such as peripheral, side channel, turbine, traction and vortex compressor/pump. Even though the efficiency of RFP/RFC is usually less than 50 per cent based on past design experience, they have found wide applications in automotive and aerospace fuel pumping, booster systems, water supply, agricultural industries, shipping and mining, chemical and food stuffs industries, and regulation of lubrication and filtering. RFCs have been proposed for use in hydrogen gas pipelines and as helium compressors for cryogenic applications in space vehicles. RFTs are used as accessory drives on aircraft and missiles. With the aim of improving the performance and efficiency of an RFP, this paper proposes an improved and modified theoretical model that can explain the change in the circulatory velocity caused by variation in channel area. All previous works concentrated on the fully developed flow region in the RFP and this work expands consideration to the developing region. Furthermore, in order to make the above-suggested model a closed problem, several loss models were assumed and the results of predictions were compared with experimental and CFD data.

scholarly journals Analysis and Design for Output Voltage Regulation in Constant-on-Time-Controlled Fly-Buck Converter

Electronics ◽  
2021 ◽  
Vol 10 (16) ◽  
pp. 1886
Author(s):  
Younghoon Cho ◽  
Paul Jang
Keyword(s):  
Output Voltage ◽  
Voltage Regulation ◽  
Design Guidelines ◽  
Buck Converter ◽  
Design Guideline ◽  
Analysis And Design ◽  
Flyback Converter ◽  
Auxiliary Power ◽  
Primary Output ◽  
Output Capacitor

Fly-buck converter is a multi-output converter with the structure of a synchronous buck converter structure on the primary side and a flyback converter structure on the secondary side, and can be utilized in various applications due to its many advantages. In terms of control, the primary side of the fly-buck converter has the same structure as a synchronous buck converter, allowing the constant-on-time (COT) control to be applied to the fly-buck converter. However, due to the inherent energy transfer principle, the primary-side output voltage regulation of COT controlled fly-buck converters may be poor, which can deteriorate the overall converter performance. Therefore, the primary output capacitor must be carefully designed to improve the voltage regulation characteristics. In this paper, a theoretical analysis of the output voltage regulation in COT controlled fly-buck converter is conducted, and based on this, a design guideline for the primary output capacitor considering the output voltage regulation is presented. The validity of the analysis and design guidelines was verified using a 5 W prototype of the COT controlled fly-buck converter for telecommunication auxiliary power supply.

scholarly journals Wind Load Reduction in Hollow Panel Arrayed Set

2016 ◽  
Vol 2016 ◽  
pp. 1-14
Author(s):  
Michalina Markousi ◽  
Dimitrios K. Fytanidis ◽  
Johannes V. Soulis
Keyword(s):  
Research Work ◽  
Flow Analysis ◽  
Flow Region ◽  
Maximum Load ◽  
Wind Load ◽  
Wind Loading ◽  
Load Reduction ◽  
Low Velocity ◽  
Approach Angle ◽  
Surface Areas

Reducing the wind loading of photovoltaic structures is crucial for their structural stability. In this study, two solar panel arrayed sets were numerically tested for load reduction purposes. All panel surface areas of the arrayed set are exposed to the wind similarly. The first set was comprised of conventional panels. The second one was fitted with square holes located right at the gravity center of each panel. Wind flow analysis on standalone arrayed set of panels at fixed inclination was carried out to calculate the wind loads at various flow velocities and directions. The panels which included holes reduced the velocity in the downwind flow region and extended the low velocity flow region when compared to the nonhole panels. The loading reduction, in the arrayed set of panels with holes ranged from 0.8% to 12.53%. The maximum load reduction occurred at 6.0 m/s upwind velocity and 120.0° approach angle. At 30.00 approach angle, wind load increased but marginally. Current research work findings suggest that the panel holes greatly affect the flow pattern and subsequently the wind load reduction. The computational analysis indicates that it is possible to considerably reduce the wind loading using panels with holes.

Investigation of the Matching Relation Between Impeller and Flow Channel of Regenerative Flow Pumps

2021 ◽  
Author(s):  
Qianqian Li ◽  
Chengshuo Wu ◽  
Bo Qian ◽  
Peng Wu ◽  
Bin Huang ◽  
...  
Keyword(s):  
Performance Optimization ◽  
Cfd Simulation ◽  
Flow Channel ◽  
Longitudinal Vortex ◽  
Exchange Flow ◽  
Low Velocity ◽  
Matching Mechanism ◽  
Regenerative Flow ◽  
Flow Pump ◽  
Matching Relation

Abstract As a specific radial flow pump, the regenerative flow pump (RFP) usually has a low efficiency. In this study, in order to explore the matching mechanism, three cases with various matching relations were investigated by the methods of theoretical calculation, computational fluids dynamics (CFD) simulation, and experiment test. The results illustrate that the theoretical prediction, numerical simulation and experimental data are in good agreement. Furthermore, when the matching relation expressed by a ratio of the channel's and blade's radial length is equal to 1, the geometrical profiles of RFP can well guide the circulation flow into the channel at large radii and into the impeller at small radii, forming intense longitudinal vortex. The steady, strong exchange flow is characterized by the inflow and outflow regions approximately half of the iso-surface. The axial vortex motion without apparent flow separation and irregular flow is observed in the impeller, a low velocity annulus exists in the medium radii of the impeller without other distinct velocity clouds, and a low velocity strip and a high velocity annulus in the channel are respectively performed along the blade's pressure surface and the channel's outer radii. All of this corresponds to the best pump's performance and the largest efficiency of the impeller and channel. This work promotes a systematical understanding of the matching mechanism between impeller and flow channel in the RFP and could provide some reference for the design and performance optimization for RFP.

Investigation on the Energy Exchange Characteristics of the Regenerative Flow Pump in an Automobile Fuel System

2020 ◽  
Vol 142 (11) ◽  
Author(s):  
Qian-qian Li ◽  
Guo-shou Zhao ◽  
Cheng-shuo Wu ◽  
Peng Wu ◽  
Da-zhuan Wu ◽  
...  
Keyword(s):  
Energy Exchange ◽  
Cfd Simulation ◽  
Longitudinal Vortex ◽  
Axial Distance ◽  
Exchange Flow ◽  
Circulation Flow ◽  
Computational Fluids Dynamics ◽  
And Performance ◽  
Regenerative Flow ◽  
Flow Pump

Abstract The flow inside the regenerative flow pump (RFP) is quite complex. This study investigated four pump models with various geometrical dimensions to explore the energy exchange characteristics. A computational fluids dynamics (CFD) simulation and the experiment were carried out. The results illustrate that the pressure growth mode in the impeller is consistent with the channels, which confirms the circulation flow existing in the pump. Furthermore, it is found that the circulation flow that features with longitudinal vortexes can be evaluated quantitatively by combining the analyses of the dimensionless axial distance, circulation number and entropy production. A smaller axial distance indicates that more flow is involved in the circulation and the intensity of the longitudinal vortex is enhanced; a large circulation number accompanied by a small dissipation loss could result in a satisfactory exchange flow. Therefore, the largest circulation number, least amount of dissipation, and shortest distance lead to the highest head and efficiency in the model with V-shaped blades and an increased impeller height. This work establishes a deeper understanding of the energy exchange mechanism and could serve as a reference for the geometrical design and performance reinforcement of RFP.

Analysis and Design of a Lightweight High Specific Power Two-Stroke Polygon Engine

2013 ◽  
Vol 136 (4) ◽  
Author(s):  
K. R. Anderson ◽  
A. Clark ◽  
D. Forgette ◽  
M. Devost ◽  
R. Okerson ◽  
...  
Keyword(s):  
Compression Ratio ◽  
Air Flow ◽  
Flow Analysis ◽  
Weight Ratio ◽  
System Level ◽  
Specific Power ◽  
Kinematic Modeling ◽  
Analysis And Design ◽  
Piston Speed ◽  
Piston Displacement

Current trends in engine design have pushed the state of the art regarding high power-to-weight ratio gasoline engines. Newly developed engine systems have a power-to-weight ratio near 1 hp per pound. The engine configuration presented herein makes it possible to package a large number of power producing pistons in a small volume, resulting in a power-to-weight ratio near 2 hp per pound, which has never before been realized in a production engine. The analysis and design of a lightweight two-stroke 6-sided in-plane polygon engine having a geometric compression ratio of 15.0, an actual compression ratio of 8.8, and a piston speed of 3500 ft/min are presented in this investigation. Typical results show that for a hexagonal engine with 2 in. diameter pistons and 1.25 in. stroke, a single piston displacement is 7.85 cubic in., while the total engine displacement is 47. 1 cubic in. Full power at 12,960 rpm at an air flow rate of 353 cubic feet per minute affords 0.444 cubic ft/min/hp for specific power. For an efficiency of 21%, the blower power is 168 hp. Our air-flow analysis shows that the power of the engine does not depend on the number of pistons, but rather on the volume of the gas-air mixture which passes through the engine. System level engineering of power output, kinematic modeling, air-flow modeling, efficiency, scavenging predictions, crankshaft sizing, and weight estimates are presented.

scholarly journals Theoretical analysis and design guideline for focusing subwavelength gratings

2015 ◽  
Vol 23 (3) ◽  
pp. 2639 ◽  
Author(s):  
Xiaofeng Duan ◽  
Guren Zhou ◽  
Yongqing Huang ◽  
Yufeng Shang ◽  
Xiaomin Ren
Keyword(s):  
Theoretical Analysis ◽  
Design Guideline ◽  
Analysis And Design ◽  
Subwavelength Gratings
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