A New Practical Approach to the Design of Industrial Axial Fans: Part I — Tube-Axial Fans With Very Low Hub-to-Tip Ratio

2019 ◽  
Author(s):  
Massimo Masi ◽  
Andrea Lazzaretto
Keyword(s):  
Rotational Speed ◽  
High Efficiency ◽  
Design Method ◽  
Pressure Coefficient ◽  
Experimental Tests ◽  
Aerodynamic Load ◽  
Blade Design ◽  
Axial Fan ◽  
Flow Rate Coefficient ◽  
Axial Fans

Abstract This paper presents a simple but complete design method to obtain arbitrary vortex design tube-axial fans starting from fixed size and rotational speed. The method couples the preliminary design method previously suggested by the authors ago with an original revised version of well-known blade design methods taken from the literature. The aim of this work is to verify the effectiveness of the method in obtaining high efficiency industrial fans. To this end, the method has been applied to a 315mm rotor-only tube-axial fan having the same size and rotational speed, and a slightly higher flow rate coefficient, as another prototype previously designed by the authors, which was demonstrated experimentally to noticeably increase the pressure coefficient of an actual 560mm industrial fan. In contrast, no constraints are imposed on the hub-to-tip ratio and pressure coefficient. The new design features a hub-to-tip ratio equal to 0.28 and radially stacked blades with aerodynamic load distribution corresponding to a roughly constant swirl at rotor exit. The ISO-5801 experimental tests showed a fan efficiency equal to 0.68, which is 6% higher than that of the previous prototype. The pressure coefficient is lower, but still 12% higher than that of the benchmark 560mm industrial fan.

A New Practical Approach to the Design of Industrial Axial Fans: Tube-Axial Fans With Very Low Hub-to-Tip Ratio

2019 ◽  
Vol 141 (10) ◽  
Author(s):  
Massimo Masi ◽  
Andrea Lazzaretto
Keyword(s):  
Rotational Speed ◽  
High Efficiency ◽  
Design Method ◽  
Pressure Coefficient ◽  
Experimental Tests ◽  
Aerodynamic Load ◽  
Blade Design ◽  
Axial Fan ◽  
Flow Rate Coefficient ◽  
Axial Fans

This paper presents a simple but complete design method to obtain arbitrary vortex design tube-axial fans starting from fixed size and rotational speed. The method couples the preliminary design method previously suggested by the authors with an original revised version of well-known blade design methods taken from the literature. The aim of this work is to verify the effectiveness of the method in obtaining high-efficiency industrial fans. To this end, the method has been applied to a 315 mm rotor-only tube-axial fan having the same size and rotational speed, and a slightly higher flow rate coefficient, as another prototype previously designed by the authors, which was demonstrated experimentally to noticeably increase the pressure coefficient of an actual 560 mm industrial fan. In contrast, no constraints are imposed on the hub-to-tip ratio and pressure coefficient. The new design features a hub-to-tip ratio equal to 0.28 and radially stacked blades with aerodynamic load distribution corresponding to a roughly constant swirl at rotor exit. The ISO-5801 experimental tests showed fan efficiency equal to 0.68, which is 6% higher than that of the previous prototype. The pressure coefficient is lower, but still 12% higher than that of the benchmark 560 mm industrial fan.

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.

Derivative Design of Axial Fan Range: From Academia to Industry

2016 ◽  
Author(s):  
Tommaso Bonanni ◽  
Lucio Cardillo ◽  
Alessandro Corsini ◽  
Giovanni Delibra ◽  
Anthony G. Sheard ◽  
...  
Keyword(s):  
Performance Prediction ◽  
Good Accuracy ◽  
Design Method ◽  
Three Dimensional ◽  
Correct Prediction ◽  
Preliminary Design ◽  
Axial Fan ◽  
Data Set ◽  
Axial Fans ◽  
Relative Errors

The work presented in this paper concerns a useful method for axial fans preliminary design based on the “Derivative Design” concept. The emphasis is, on one side, on education and, on the other, on the practical help that such method can provide in the early preliminary design process. A complete data set of an axial fan measured with ISO 5801 standards is the start point for the investigation and the prediction of the multiple possible performance that different fan configurations can provide, in terms of dimensionless duty coefficients. In particular, configurations with different number of blades, and hence of solidity, are studied. The typical options of derivative design are explored and relations for performance prediction are presented. A detailed description of the derivative design methodology is followed by tests and validation. The tools employed are a fully three dimensional code, the Advanceded Actuator Disk Mode (AADM), and two other in-house codes, the Meanline Axisymmetric Calculation (MAC) and Axisymmetric Laboratory (AXLAB). Results of the derivative design method are reported, showing a good accuracy against the AADM data. The MAC and AXLAB ensure still acceptable results when increasing the solidity of the machine. On the contrary, a decrease of solidity leads to higher relative errors in the prediction of the load coefficient. In conclusion, an exploration of the possible fields of operation of a blade profile can be carried out by a correct prediction of the stage diffusion factor.

A Solution for Experimental Modeling the Axial Fans With High Efficiency and Reduced Noise

2020 ◽  
Author(s):  
Victorita Radulescu
Keyword(s):  
High Efficiency ◽  
Experimental Tests ◽  
Rotation Velocity ◽  
Industrial Applications ◽  
Rotor Blades ◽  
Experimental Results ◽  
Computational Method ◽  
Maximum Efficiency ◽  
Axial Fan ◽  
Experimental Stand

Abstract Present paper describes some experimental results obtained for modeling an axial fan with newly designed blade profiles, having high efficiency, low vibrations and noise. The axial fan was firstly designed by computational method, during a research project with our industrial partner SAVEB SA. One of the company objectives is represented by the production of the axial industrial fans, dedicated to different users to eliminate the smoke and the air pollutants from industrial halls, according to their specific needs. In the beginning, are presented some aspects of the theoretical aspects used in the numerical modeling for designing the rotor blades. Some considerations concerning the selection of the incidence angles of 10°, 15°, and 20° are mentioned. The profiles were selected from the recommended schemes, for different industrial applications, as the industrial halls for the air or gas circulation without corrosive, abrasive, or toxic agents, metallic dust, or with crowding/sticking suspensions contents. For this type of axial fan, the content of suspensions should not exceed 50 mg/m3. Further is presented the experimental stand, in conformity with actual standards, STAS 7466-84 and DIN 24163, equipped with a hydrometer with an error less than 3%, barometer with an error less than 1 mm Hg, stroboscope and tachometer with an error less 0,5% from the total rotation velocity, two voltmeters, with an error less 0,5, two wattmeters, etc. For the experimental tests was selected a fan with a diameter of 630 mm, which as standard execution has a maximum efficiency of 56%, in six different constructive variants: a rotor with 12 profiles and directory device with 11 blades, with 6 blades and directory device, etc. As the first variant of the rotor’s profiles has been used two solutions for the realization as two technological options, both of them tested in the laboratory. There are detailed some schemes adopted for the measurements and tests, and finally the adopted solution for measuring different characteristic parameters like efficiency, noise, and vibrations produced by the axial fan. Next are illustrated part of the measurement reports and the corresponding charts. Of the total amount of experimental results were selected for measuring scheme III and IV for their optimum energetic characteristics and high efficiency. All four diagrams are presented for both selected solutions used in the realization of the fan rotor blades. Finally, some conclusions and references are presented.

A New Practical Approach to the Design of Industrial Axial Fans: Part II — Forward-Swept Blades With Low Hub-to-Tip Ratio

2019 ◽  
Author(s):  
Massimo Masi ◽  
Andrea Lazzaretto
Keyword(s):  
Design Method ◽  
Pressure Coefficient ◽  
Rate Coefficients ◽  
Maximum Efficiency ◽  
Stable Operation ◽  
Pressure Curve ◽  
Simple Method ◽  
Aspect Ratios ◽  
Wide Range ◽  
Axial Fans

Abstract The authors previously suggested a simple method to design forward-swept axial-flow rotors with blades having low hub-to-tip and high aspect ratios. This design method was demonstrated experimentally to increase the aeraulic performance of a small tube-axial fan having unswept blades and 0.4 hub-to-tip ratio, while maintaining the efficiency in the entire operation range. However, the method has not yet been assessed by experimental tests of lower hub-to-tip ratio designs where the strong three-dimensionality of the actual blade passage flow could compromise its validity. This assessment is the object of the present paper, which is aimed at examining the practical effectiveness of the forward-swept blade design method for low hub-to-tip ratio tube-axial fans. To this end, past results of the authors’ work are supported here by the design of a new 315mm forward-swept industrial fan derived from the 0.28 hub-to-tip ratio design presented in Part I of this paper. The ISO-5801 aerodynamic performance tests at blade Reynolds number of approximately 60,000 show that the method permits the design of forward-swept industrial fans capable of pressure coefficients in excess of 0.02 at aeraulic efficiency well above 60%, in a wide range of flow rate coefficients and blade positioning angles. Moreover, the method allows obtaining a pressure coefficient equal to 0.021 at 70% maximum efficiency, with an improvement of both the stall margin and stable operation pressure curve of the unswept design, if applied in combination with the complete fan design method presented in Part I of this paper.

Efficiency Improvement of Industrial Fans if Operating at Off-Design Modes

2019 ◽  
Vol 7 (3) ◽  
pp. 43-51
Author(s):  
Глеб Замолодчиков ◽  
Gleb Zamolodchikov ◽  
Р. Тумашев ◽  
R. Tumashev ◽  
Н. Щеголев ◽  
...  
Keyword(s):  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
High Efficiency ◽  
Operating Mode ◽  
Rotor Blades ◽  
Aerodynamic Load ◽  
Axial Fan ◽  
Performance Factor ◽  
Wide Range

This paper’s aim is enhancement of efficiency for fans adjusting by turn of rotor blades. A high load axial fan and a fan with decreased rotor’s pitch chord ratio by reduction of blades number were investigated. Have been performed tests of the fan with design characteristics as follows: theoretical head coefficient Ht = 0,3, mass flow rate Ca = 0,4, hub’s relative diameter ν = 0.6, and with blades, graded on the law of permanent circulation. The area of effective adjustment was estimated by the performance factor value η* ≥ 0,8. When changing the stagger angles in a wide range from 26° to 70°, the area of highly economical work was in variation ranges 0,26–0,78 for the mass flow rate Ca , and 0,24–0,5 for the theoretical head coefficient Ht accordingly. Tests of fans with a reduced blades number in the rotor (12 instead of 16 for the original fan) has showed that under the same stagger angles the fan’s high-efficiency operating mode is approximately in the same range of Ca variation at slightly reduced values of theoretical head coefficient. Maximal performance factor has increased on 2.5%. Decreasing the number of rotary blades, simplifying the turning mechanism and reducing the weight are possible in the design of fans with increased values of aerodynamic load coefficients.

scholarly journals The best efficiency point of an axial fan at low-pressure conditions

2021 ◽  
Vol 13 (3) ◽  
pp. 168781402110011
Author(s):  
Jose J Corona ◽  
Osama Mesalhy ◽  
Louis Chow ◽  
Quinn Leland ◽  
John P Kizito
Keyword(s):  
Optimal Design ◽  
Performance Measures ◽  
Flow Rate ◽  
Rotational Speed ◽  
Ambient Pressure ◽  
Axial Flow ◽  
Axial Fan ◽  
Electromechanical Actuators ◽  
Aerospace Applications ◽  
Axial Fans

In the current work, the objective is to determine the best efficiency point (BEP) of an axial fan using CFD. Analyzing the performance of the fan based upon the parameters chosen can lead to the optimal design of an axial flow fan for aerospace applications where the ambient pressure varies rapidly. The 2-bladed fan chosen for the study is the Propimax 2L which is considered the base fan used for comparison of all the results of the work. The set of parameters tested were fan rotational speed, ambient pressure conditions, blade count, and the airfoil design. All the performance measures were based on overall fan efficiency. The results yield the following: an increased rotational speed led to higher efficiencies, the most efficient ambient pressure of which the fan can perform is 0.7 atm, a 5-bladed fan configuration produced the highest efficiency, and airfoil selection is critical for fan efficiency enhancements. The results demonstrated that at 0.7 atm the fan efficiency is the highest due to the changes in power consumption to the density effect. A key finding in the work is that higher blade counts do not necessarily lead to higher performing axial fans. A high cambered airfoil provided a higher flow rate at free delivery than that of the Propimax 2L design, but the rotorcraft airfoil did not yield favorable results. The analysis is focused on the fan design of cooling of the electromechanical actuators (EMAs).

Influence of blade skew on axial fan component noise

2017 ◽  
Vol 16 (4-5) ◽  
pp. 418-430 ◽  
Author(s):  
Gert Herold ◽  
Florian Zenger ◽  
Ennes Sarradj
Keyword(s):  
Test Chamber ◽  
Microphone Arrays ◽  
Blade Design ◽  
Axial Fan ◽  
Sound Sources ◽  
Acoustic Characteristics ◽  
Radiated Noise ◽  
Trailing Edges ◽  
Axial Fans ◽  
Operating Points

Microphone arrays can be used to detect sound sources on rotating machinery. For this study, experiments with three different axial fans, featuring backward-skewed, unskewed, and forward-skewed blades, were conducted in a standardized fan test chamber. The measured data are processed using the virtual rotating array method. Subsequent application of beamforming and deconvolution in the frequency domain allows the localization and quantification of separate sources, as appear at different regions on the blades. Evaluating broadband spectra of the leading and trailing edges of the blades, phenomena governing the acoustic characteristics of the fans at different operating points are identified. This enables a detailed discussion of the influence of the blade design on the radiated noise.

A Method Combined with the Genetic Algorithm for Design of High Efficiency Propeller

2014 ◽  
Vol 709 ◽  
pp. 172-175
Author(s):  
Song Xiang ◽  
Wei Ping Zhao ◽  
Li Guo Zhang ◽  
Gang Tong
Keyword(s):  
Genetic Algorithm ◽  
Rotational Speed ◽  
Pitch Angle ◽  
Present Method ◽  
High Efficiency ◽  
Design Method ◽  
General Aviation ◽  
Li Ion Battery ◽  
Li Ion ◽  
Mach Numbers

In this paper, a design method combined with the genetic algorithm is proposed to design the propeller of general aviation aircraft. The inputs of this method are the cruise speed, rotational speed, propeller diameter, number of blade, thrust, Reynolds and Mach numbers. The chord and pitch-angle angle distributions along the blade are the outputs of this method. The propeller of a kind of Li-ion battery powered aircraft is designed by the present method.

scholarly journals A Parametric Blade Design Method for High-Speed Axial Compressor

Aerospace ◽  
2021 ◽  
Vol 8 (9) ◽  
pp. 271
Author(s):  
Hengtao Shi
Keyword(s):  
Design Space ◽  
Flow Characteristic ◽  
Design Method ◽  
Compressor Blade ◽  
Design Parameters ◽  
Blade Design ◽  
Axial Fan ◽  
Geometry Design ◽  
Design Variables ◽  
Blade Geometry

The blade geometry design method is an important tool to design high performance axial compressors, expected to have large design space while limiting the quantity of design variables to a suitable level for usability. However, the large design space tends to increase the quantity of the design variables. To solve this problem, this paper utilizes the normalization and subsection techniques to develop a geometry design method featuring flexibility and local adjustability with limited design variables for usability. Firstly, the blade geometry parameters are defined by using the normalization technique. Then, the normalized camber angle f1(x) and thickness f2(x) functions are proposed with subsection techniques used to improve the design flexibility. The setting of adjustable coefficients acquires the local adjustability of blade geometry. Considering the usability, most of the design parameters have clear, intuitive meanings to make the method easy to use. To test this developed geometry design method, it is applied in the design of a transonic, two flow-path axial fan component for an aero engine. Numerical simulations indicate that the designed transonic axial fan system achieves good efficiency above 0.90 for the entire main-flow characteristic and above 0.865 for the bypass flow characteristic, while possessing a sufficiently stable operation range. This indicates that the developed design method has a large design space for containing the good performance compressor blade of different inflow Mach numbers, which is a useful platform for axial-flow compressor blade design.

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