Design for high efficiency of low-pressure axial fans: Use of blade sweep and vortex distribution

2021 ◽  
Author(s):  
Jie Wang
Keyword(s):  
High Efficiency ◽  
Low Pressure ◽  
Axial Fans

RHELP (Regenerative High Efficiency Low Pressure) Air Purification System

2009 ◽  
Author(s):  
Chang-Yu Wu ◽  
Brian Damit ◽  
Qi Zhang ◽  
Myung-Heui Woo ◽  
Wolfgang Sigmund ◽  
...  
Keyword(s):  
High Efficiency ◽  
Low Pressure ◽  
Air Purification ◽  
Purification System

Development of a New Design Method for High Efficiency Swept Low Pressure Axial Fans With Small Hub/Tip Ratio

2014 ◽  
Author(s):  
Thore Bastian Lindemann ◽  
Jens Friedrichs ◽  
Udo Stark
Keyword(s):  
High Efficiency ◽  
Design Method ◽  
Tangential Velocity ◽  
Pressure Rise ◽  
Low Pressure ◽  
Aerodynamic Performance ◽  
Low Noise ◽  
Angle Distribution ◽  
Sweep Angle ◽  
Reduced Pressure

For a competitive low pressure axial fan design low noise emission is as important as high efficiency. In this paper a new design method for low pressure fans with a small hub to tip ratio including blade sweep is introduced and discussed based on experimental investigations. Basis is an empirical axial and tangential velocity distribution at the rotor outlet combined with a distinctive sweep angle distribution along the stacking line. Several fans were designed, built and tested in order to analyze the aerodynamic as well as the aeroacoustic behavior. For the aerodynamic performance particular attention was paid to compensate the influence of reduced pressure rise and efficiency due to increasing blade sweep. This was achieved by a method of increasing the blade chord depending on the local sweep angle which is based on single airfoil data. The tested fans without this compensation revealed a significant noise reduction effect of up to approx. 6 dB(A) for a tip sweep angle of 64° which was accompanied by an unsatisfactory effect of reduced overall aerodynamic performance. The second group of fans did not only confirm the method of the aerodynamic compensation by a nearly unchanged pressure rise and efficiency characteristic but also revealed an increased aeroacoustic benefit of in average 9.5 dB(A) compared to the unswept version. Beside the overall characteristics the individual differences between the designs are also discussed using results of wall pressure measurements which show some significant changes of the blade tip flow structure.

Development of composite filters with high efficiency, low pressure drop, and high holding capacity PM2.5 filtration

2019 ◽  
Vol 212 ◽  
pp. 699-708 ◽  
Author(s):  
De-Qiang Chang ◽  
Chi-Yu Tien ◽  
Chien-Yuan Peng ◽  
Min Tang ◽  
Sheng-Chieh Chen
Keyword(s):  
Pressure Drop ◽  
High Efficiency ◽  
Low Pressure

scholarly journals Experimental investigation of an annular diffuser for axial fans at different inflow profiles

2017 ◽  
Vol 21 (suppl. 3) ◽  
pp. 553-564
Author(s):  
Johannes Walter ◽  
Dieter Wurz ◽  
Stefan Hartig ◽  
Martin Gabi
Keyword(s):  
Power Plants ◽  
High Efficiency ◽  
Outer Wall ◽  
Pressure Recovery ◽  
Shear Stresses ◽  
Axial Fan ◽  
Mean Velocity ◽  
Annular Diffuser ◽  
Axial Fans ◽  
Wall Shear

Axial fans are used in power plants for fresh air supply and flue gas transport. A typical configuration consists of an axial fan and annular diffuser which connects the fan to the following piping. In order to achieve a high efficiency of the con-figuration, not only the components have to be optimized but also their interaction. The present study focuses on the diffuser of the configuration. Experiments are performed on a diffuser-piping configuration to investigate the influence of the velocity profile at the fan outlet on the pressure recovery of the configuration. Two different diffuser inlet profiles are generated, an undisturbed profile and a profile with the typical outlet characteristics of a fan. The latter is generated by the superposition of screens in the inlet zone. The tests are conducted at a high Reynolds number (Re ? 4?105). Mean velocity profiles and wall shear stresses are measured with hydraulic methods (Prandtl and Preston tubes). The results show that there is a lack of momentum at the outer wall of the diffuser and high shear stresses at the inner wall in case of the undisturbed inflow profile. For the typical fan outlet profile it is vice versa. There are high wall shear stresses at the outer wall while the boundary layer of the inner wall lacks momentum. The pressure recovery of the undisturbed inflow configuration is in good agreement with other studies.

Low-pressure mercury lamp pumped atomic iodine laser of high efficiency

1979 ◽  
Vol 28 (2) ◽  
pp. 202-206 ◽  
Author(s):  
K.J. Witte ◽  
P. Burkhard ◽  
H.R. Lüthi
Keyword(s):  
High Efficiency ◽  
Low Pressure ◽  
Mercury Lamp ◽  
Iodine Laser ◽  
Atomic Iodine

Computational Modeling of Low-Pressure Fan Flows

2000 ◽  
Author(s):  
Siddharth Thakur ◽  
Wanlai Lin ◽  
Jeffrey Wright ◽  
Wei Shyy ◽  
Ron Lievens
Keyword(s):  
Pressure Rise ◽  
Low Pressure ◽  
Flow Fields ◽  
Numerical Dissipation ◽  
Computational Tool ◽  
Axial Fan ◽  
Static Efficiency ◽  
Blade Shape ◽  
Axial Fans ◽  
Mass Flow Rates

A CFD-based computational tool is used to analyze flows in axial fans. Computed results for an axial fan flow field for one particular blade shape are presented; certain global quantities such as the mass-averaged pressure rise and the static efficiency available from test data for different mass flow rates are used to evaluate the trends predicted by the CFD results. The characteristic feature of the fan flow fields presented here is a very low pressure rise; due care is exercised to ensure that grid dependence and numerical dissipation do not smear out the key features of the computed flow fields.

The pulse reactor—A high-efficiency, high-precision low-pressure MOCVD machine

1988 ◽  
Vol 93 (1-4) ◽  
pp. 201-206 ◽  
Author(s):  
J. Van Suchtelen ◽  
J.E.M. Hogenkamp ◽  
W.G.J.H.M. Van Sark ◽  
L.J. Giling
Keyword(s):  
High Precision ◽  
High Efficiency ◽  
Low Pressure ◽  
Pulse Reactor ◽  
Low Pressure Mocvd

Gasdynamic Design Numerical Optimization of High-Loaded Subsonic Stages for Low Pressure Steam Turbine

2013 ◽  
Author(s):  
Aleksei Dolganov ◽  
Alexander Nekrasov
Keyword(s):  
Steam Turbine ◽  
Power Plants ◽  
High Efficiency ◽  
Low Pressure ◽  
Large Capacity ◽  
Low Pressure Turbine ◽  
Relative Pitch ◽  
Pressure Steam ◽  
Basic Characteristics

Modern large capacity steam turbine for fossil power plants should have a high efficiency to be competitive in today’s tough market. It should be compact, with a smaller mass for reducing cost. In these circumstances, an effective solution is to create a large capacity steam turbine that consists of integrated high-intermediate-pressure turbine (HIPT) and one low-pressure turbine (LPT). Greater heat drop as compared to a conventional turbine shall be provided in LPT of such steam turbine. With this rather high efficiency of the low-pressure turbine should be provided. The performance of LPT depends not only on the efficiency of trans- and supersonic stages, but also on the efficiency of subsonic upstream stages. At a time when the overall heat drop in the low-pressure turbine is increased, role of the upstream subsonic stages also increases, provided that the design of stages L-0 and L-1 is maintained. This paper presents results of numerical simulation of an optimized subsonic stages section for a new low-pressure steam turbine. Simulation results of a conventional subsonic stages section are presented for comparison. Stages of the optimized subsonic section have a number of features: increased disposable heat drop, enlarged relative pitch, spline representation of sections of blade profiles, 3D airfoil design. The comparison of normalized integral basic characteristics, plots of the main parameters on the blade height, diagrams of the normalized pressure in individual cylindrical sections is given for optimized and conventional cases.

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