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.

Preliminary Design of Axial Fans at Off-Design Working Points

2014 ◽  
Author(s):  
Matthias Semel ◽  
Julien Grilliat ◽  
Antonio Delgado
Keyword(s):  
Best Practice ◽  
Preliminary Design ◽  
Hydraulic Efficiency ◽  
Axial Fan ◽  
Free Vortex ◽  
Best Practice Guidelines ◽  
Work Distribution ◽  
Theoretical Predictions ◽  
Axial Fans ◽  
Straight Lines

An analytical formulation for axial fan performances at and off design point is proposed for an arbitrary work distribution. It is shown that the total pressure, total-to-static pressure and hydraulic efficiency characteristics can be described by means of hyperbola, straight lines and parabola. This formulation is applied to axial fans with free vortex work distributions, allowing a theoretical study onto the influence of the hub-to-tip ratio. Theoretical predictions are compared with numerical simulations. Good qualitative agreements are found. Conclusions onto the best practice guidelines for the design of axial fan according to a free vortex work distributions are presented.

scholarly journals Experiment-Based Preliminary Design Guidelines for Consideration of Profile Vortex Shedding From Low-Speed Axial Fan Blades

2021 ◽  
Vol 143 (6) ◽  
Author(s):  
Gábor Daku ◽  
János Vad
Keyword(s):  
Vortex Shedding ◽  
Design Guidelines ◽  
Preliminary Design ◽  
Axial Fan ◽  
Noise Emission ◽  
Blade Vibration ◽  
Low Speed ◽  
Blunt Trailing Edge ◽  
Axial Fans ◽  
Semi Empirical

Abstract This paper presents hot-wire measurements in a wind tunnel, close downstream of basic models of blade sections being representative for low-speed, low-Reynolds number axial fans, in order to explore the signatures of vortex shedding (VS) from the blade profiles. Using the Rankine-type vortex approach, an analytical model was developed on the velocity fluctuation represented by the vortex streets, as an aid in evaluating the experimental data. The signatures of profile VS were distinguished from blunt trailing-edge VS based on Strouhal numbers obtained from the measurements in a case-specific manner. Utilizing the experimental results, the semi-empirical model available in the literature for predicting the frequency of profile VS was extended to low-speed axial fan applications. On this basis, quantitative guidelines were developed for the consideration of profile VS in preliminary design of axial fans in the moderation of VS-induced blade vibration and noise emission.

scholarly journals Prediction of Longitudinal Curvature Radius of 3D Surface Based on Quadratic Relationship between Strain and Coordinates in Continuous Roll Forming

Metals ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1249
Author(s):  
Jiaxin Gao ◽  
Dongye He ◽  
Lirong Sun ◽  
Xi Zhang ◽  
Zhongyi Cai
Keyword(s):  
Convex Surface ◽  
Design Method ◽  
Three Dimensional ◽  
Roll Forming ◽  
Curvature Radius ◽  
Forming Process ◽  
3D Surface ◽  
Quadratic Relationship ◽  
Relative Errors ◽  
Roll Gap

Continuous roll forming (CRF) is a new method for the rapid forming of three-dimensional (3D) surfaces developed in recent years, and the significant advantage of CRF compared with traditional die forming is that the longitudinal dimension of the sheet metal is not limited. By controlling the curvature radius and gap shape of upper and lower bending rolls, three-dimensional parts with different shapes and sizes can be precisely formed. When the elastic deformation is ignored during the forming process, the transversal curvature radius of the three-dimensional surface is consistent with the radius of the roll gap centerline. Therefore, the calculation of longitudinal curvature radius is the key to improve the accuracy of the 3D surface in CRF. In this paper, the basic principle of CRF is described. The modified formulas for calculating the longitudinal curvature radius of convex and saddle surfaces based on the quadratic relationship between the strain and coordinates are deduced in detail, and the corresponding design method of the roll gap is derived. Furthermore, the mathematical equations of convex and saddle surfaces are given. Through numerical simulation and theoretical analysis, it is found that the relative errors of the longitudinal centerline radius are reduced from 13.67% before modification to 4.35% after modification for a convex surface and 6.81% to 0.41% for a saddle surface when the transversal curvature radius is 800 mm and the compression ratio is 5%. The experimental and measured results indicate that the shapes of formed parts are more consistent with the target parts after modification, which further proves the applicability of the modified formulas.

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 Experiment-Based Preliminary Design Guidelines for Consideration of Profile Vortex Shedding From Low-Speed Axial Fan Blades

2020 ◽  
Author(s):  
Gábor Daku ◽  
János Vad
Keyword(s):  
Vortex Shedding ◽  
Design Guidelines ◽  
Preliminary Design ◽  
Axial Fan ◽  
Noise Emission ◽  
Blade Vibration ◽  
Low Speed ◽  
Blunt Trailing Edge ◽  
Axial Fans ◽  
Semi Empirical

Abstract The paper presents hot wire measurements in a wind tunnel, close downstream of basic models of blade sections being representative for low-speed, low-Reynolds-number axial fans, in order to explore the signatures of vortex shedding (VS) from the blade profiles. Using the Rankine-type vortex approach, an analytical model was developed on the velocity fluctuation represented by the vortex streets, as an aid in evaluating the experimental data. The signatures of profile VS were distinguished from blunt-trailing-edge VS based on Strouhal numbers obtained from the measurements in a case-specific manner. Utilizing the experimental results, the semi-empirical model available in the literature for predicting the frequency of profile VS was extended to low-speed axial fan applications. On this basis, quantitative guidelines were developed for consideration of profile VS in preliminary design of axial fans in moderation of VS-induced blade vibration and noise emission.

Centrifugal Compressor Aerodynamic Design of Marine Engine Turbocharger by Three Dimensional Numerical Simulation

2002 ◽  
Author(s):  
Hong-Won Kim ◽  
Kook-Taek Oh ◽  
Sang-Hak Ghal ◽  
Ji-Soo Ha
Keyword(s):  
Numerical Simulation ◽  
Centrifugal Compressor ◽  
Performance Prediction ◽  
Three Dimensional ◽  
Flow Coefficient ◽  
Preliminary Design ◽  
Aerodynamic Design ◽  
Navier Stokes Equation ◽  
Slip Factor ◽  
Line Design

For the centrifugal compressor aerodynamic design of a turbocharger, first of all, the works for system matching to the engine specification must be preceded. Then, mean line design together with performance prediction should be carried out for preliminary design. In the mean line prediction, a slip factor is adopted as a function of flow coefficient and geometry instead of Wiesner’s equation, and it is found that the predicted result of slip magnitude is more accurate than that of conventional slip factor. Also, three-dimensional blade profile shape is generated on the basis of the preliminary design. The Navier-Stokes Equation solver with a turbulent model is used to find whether three-dimensionally designed geometry is reasonable by analyzing loading distribution of the blade. By investigating diffuser flow field of the simulated result, the diffuser inlet and exit angles were modified for the flow to move smoothly along the diffuser geometry. Modified performance prediction results shows better than those of original specification. Consequently, off design performance prediction results and numerical simulation result show good agreement with the experimental data. The modified design results show more increased compression ratio and efficiency than those of previous design results. The increased choke margin has made a stable operating range larger.

Inverse Analytical and Computational Design Method Applied to a Low Pressure Axial Fan

2010 ◽  
Author(s):  
Mihai Miclea-Bleiziffer ◽  
Philipp Epple ◽  
Antonio Delgado
Keyword(s):  
Design Method ◽  
Computational Design ◽  
Integrated Approach ◽  
Low Pressure ◽  
Inverse Design ◽  
Axial Fan ◽  
Rotating Speed ◽  
Design And Optimization ◽  
Research Fields ◽  
Axial Fans

Nowadays precise and reliable tools for designing and optimizing turbomachines have a high impact on industrial and research fields. The design methods of turbomachines follow usually two main paths: direct design, where performances are achieved by iteratively modifying a given geometry, and inverse design where performance characteristics are prescribed and the proper geometry for reaching them is found (usually using analytical methods). Both of these methods are used today in research and development and they are coupled with numerical simulations (CFD) for shorter design cycles. This paper proposes an inverse design approach for low pressure axial fans based upon performance equations, namely the equations for total-to-static pressure and efficiency. To validate our approach we use numerical simulation of the axial fan in a virtual test rig. Combining inverse design with the CFD for its validation offers an integrated approach for improving the design in the development phase. In the first step analytical energy equations are derived for a blade cascade section and then integrated over the blade surface, i.e. from hub to tip radii, providing a dependency of the theoretical performances characteristics such as for the pressure and the efficiency, as a function of the flow-rate, rotating speed and the outer dimensions and blade angles of the machine. The next step computes inversely the main outer dimensions and blade angles of the geometry required for reaching the performance. In the final design step the blade shape is computed inversely using a NACA 4 Digit camber as it will be shown in the paper upon the required blade angles and other constrains of the cascade. The final shape is generated in CAD software-program and then a proper computational grid is generated so that it can be finally simulated with a commercial Navier-Stokes solver for the complete pressure and efficiency characteristics. The aim of this study is to offer general conclusions about the analytical influence of certain geometry parameters on the design and optimization of axial fans of this type. The last step for the proposed design method is typically the experimental validation with prototypes which will be not covered in this study.

A Criterion for the Preliminary Design of High-Efficiency Tube-Axial Fans

2016 ◽  
Author(s):  
Massimo Masi ◽  
Stefano Castegnaro ◽  
Andrea Lazzaretto
Keyword(s):  
High Efficiency ◽  
Low Cost ◽  
Pressure Rise ◽  
Maximum Size ◽  
Industrial Applications ◽  
Design Criterion ◽  
Preliminary Design ◽  
Axial Fan ◽  
Axial Fans ◽  
Analytical Formulas

Tube-axial fans are widely used in industrial applications because of their compactness, simplicity, and low cost. However, the achievable fan pressure rise is generally penalised by the absence of a straightener and diffuser, and the consequent waste of tangential and axial dynamic pressures at the fan outlet. The corresponding fan efficiency drop might not comply with stringent regulations like the European Directive for energy-related products. Thus, operation ranges of high efficiency need to be clearly defined in the preliminary design phase, especially when constraints on maximum size and/or rotational speed are imposed. This paper proposes analytical formulas and charts to evaluate the efficiency of the tube-axial fan configuration (with or without tail-cone diffuser) when constraints on fan size and/or speed are additional design requirements. The analytical formulas and charts have been validated against experimental data. On this basis, a preliminary design criterion is suggested for high-efficiency tube-axial fans featuring arbitrary vortex design blades of constant swirl type. The criterion is used to design a 315 mm low-to-medium pressure tube-axial fan that is able to operate at a constant aeraulic efficiency peak of approximately 0.6 for blade positioning angles in the range 20° to 30°.

Three-dimensional image analysis and visualization in confocal light microscopy

1993 ◽  
Vol 51 ◽  
pp. 158-159
Author(s):  
J. K. Samarabandu ◽  
R. Acharya ◽  
D. R. Pareddy ◽  
P. C. Cheng
Keyword(s):  
Depth Perception ◽  
Computer Graphic ◽  
Three Dimensional ◽  
Cellular Organization ◽  
Data Set ◽  
Computational Burden ◽  
Interactive Operation ◽  
Cell Organization ◽  
Confocal Images ◽  
3D Digitization

In the study of cell organization in a maize meristem, direct viewing of confocal optical sections in 3D (by means of 3D projection of the volumetric data set, Figure 1) becomes very difficult and confusing because of the large number of nucleus involved. Numerical description of the cellular organization (e.g. position, size and orientation of each structure) and computer graphic presentation are some of the solutions to effectively study the structure of such a complex system. An attempt at data-reduction by means of manually contouring cell nucleus in 3D was reported (Summers et al., 1990). Apart from being labour intensive, this 3D digitization technique suffers from the inaccuracies of manual 3D tracing related to the depth perception of the operator. However, it does demonstrate that reducing stack of confocal images to a 3D graphic representation helps to visualize and analyze complex tissues (Figure 2). This procedure also significantly reduce computational burden in an interactive operation.

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