scholarly journals Strength Analysis of a Ducted Axial Fan Blade

2018 ◽  
Vol 9 (4) ◽  
pp. 85-100
Author(s):  
Marek ROŚKOWICZ ◽  
Ryszard CHACHURSKI ◽  
Sławomir TKACZUK ◽  
Piotr LESZCZYŃSKI ◽  
Maciej MAJCHER ◽  
...  
Keyword(s):  
Stress Distribution ◽  
Numerical Calculations ◽  
Strength Analysis ◽  
Axial Fan ◽  
Optical Scanner ◽  
Geometrical Features ◽  
Simplifying Assumptions ◽  
Axial Fans ◽  
Fan Blade ◽  
And Performance

This paper presents a numerical strength analysis of a ducted axial fan blade. Ducted axial fans are a large group of fluid-flow machines. The analysis was designed to determine the causes of cyclic failures of a ventilation unit. The paper presents a reverse engineering approach to the mapping of the fan blade’s geometrical features. The geometrical features were mapped by triangulation from the scanning images produced by a 3D optical scanner. These were followed by simplifying assumptions on which the numerical calculations were based. The numerical calculations were carried out at the operating rotational speeds of the ducted axial fan’s rotor. The course of the numerical calculations is described, and their results are also presented herein. The results are represented on colour maps of stress distribution for selected structural elements of the fan blade. The stress distribution at a blade cross-section was compared to CT scans of the fractures of failed rotor blade airfoils. Final conclusions were developed which show that the design engineering process of fans should feature optimisation of the fan’s efficiency, including the strength and performance parameters, which should include the service life of the fan.

Numerical Study on the Passive Control of the Aeroelastic Response in Large Axial Fans

2016 ◽  
Author(s):  
A. Castorrini ◽  
A. Corsini ◽  
A. G. Sheard ◽  
F. Rispoli
Keyword(s):  
Passive Control ◽  
Numerical Study ◽  
Operating Conditions ◽  
Rotor Blades ◽  
Axial Fan ◽  
Strongly Coupled ◽  
Dimensional Approximation ◽  
Axial Fans ◽  
Fan Blade ◽  
And Performance

The morphing geometry concept finds interesting applications in load reduction and performance increasing for wings and rotor blades in off-design conditions. Here we report a numerical study on the effect that a passive morphing system (made by an elastic-low stiffness surface) has on the sectional load and flowfield, when it is applied to the trailing edge of an axial fan. We obtain the results extracting the section of the fan blade and test it in the 2D cascade, with and without the elastic device, in different operating conditions. Keeping in mind the two-dimensional approximation, it will be possible to observe how the tested device could reduce the load in off-design and high angle of attack conditions, while the same solution could introduce vibrations in design conditions. All the simulations imply the solution of the fluid-structure interaction between the incompressible, turbulent flow and the elastic structure. This solution is obtained using a finite element based, strongly coupled solver, applied to the periodic 2D domain of the section in the cascade.

A Ring Silencer Design for Reducing Noise of Axial Fan

2003 ◽  
Vol 03 (03) ◽  
pp. L259-L264
Author(s):  
Jian-Da Wu ◽  
Mingsian R. Bai
Keyword(s):  
Helmholtz Resonator ◽  
Boundary Region ◽  
Acoustic Analogy ◽  
Axial Fan ◽  
Noise Sources ◽  
Fan Noise ◽  
Fluctuating Pressure ◽  
Axial Fans ◽  
Fan Blade ◽  
Broadband Frequency

In this paper, a ring silencer design for reducing the noise of axial fans is presented. The noise sources on axial fans are usually caused by the fluctuating pressure distribution on the surface of fan blade. Most of the sources are near the trailing edge of blades or boundary region of blades. The ideation of proposed design is based on the principle of Helmholtz resonator for reducing the noise around the fan. The electro-acoustic analogy of this design is presented and simply discussed. Experimental measurement is carried out to evaluate the proposed design for reducing the axial fan noise. The result of experiment indicated that the ring silencer achieved 17 dB in blade passing frequency and 10 dB in other broadband frequency of power spectrum level.

Axial Fan Blade Tone Cancellation Using Optimally Tuned Quarter Wavelength Resonators

2009 ◽  
Vol 131 (2) ◽  
Author(s):  
Lee Gorny ◽  
Gary H. Koopmann
Keyword(s):  
Sound Field ◽  
Test Facility ◽  
Secondary Source ◽  
Axial Fan ◽  
Ducted Fan ◽  
Quarter Wavelength ◽  
Centrifugal Fans ◽  
Line Theory ◽  
Axial Fans ◽  
Fan Blade

Fan noise challenges noise control engineers in developing products ranging in scale from small ventilation systems to large turbomachines. The dominant noise source in many axial fans is the tonal noise due to rotor/stator interactions at the fundamental blade passing frequency. Flow-excited resonators have been used in the past for minimizing blade tone sound pressure levels (SPLs) generated by centrifugal fans through means of secondary source cancellation. The focus of this research is to extend that cancellation method to axial fans by attaching flow-driven quarter wavelength resonators fitted with optimal mouth perforations around the perimeter of the fan’s shroud. A ducted-fan test facility was developed to measure upstream and downstream noise radiated from a test fan. Resonators were mounted at specific locations around the fan’s shroud to obtain reductions in blade tone SPLs in both flow directions. They were driven into resonance via the unsteady pressure from the passing blades. An analytical model using transmission line theory was developed and validated experimentally to characterize the resonator’s behavior under various flow conditions and mouth geometries. This model was used to predict the resonator’s potential for reducing in-duct blade tones for specific flows and mouth perforation patterns. In a series of experiments to obtain the optimal resonator mouth perforations, it was observed that upstream and downstream SPL attenuations require different placement of the resonator mouth relative to the blade of the fan. With a single tuned resonator it was demonstrated that the fundamental blade tone SPLs can be reduced by as much as 20 dB in either the upstream or the downstream duct but not in both directions simultaneously. This behavior results when combining the resonator’s monopolelike sound field with the dipolelike sound field of the fan’s blades. Further studies are underway to extend the above method to higher pressure fans operating at speeds that generate higher order duct modes.

scholarly journals Design and analysis of the flange-bolted joint with respect to required tightness and strength

2019 ◽  
Vol 9 (1) ◽  
pp. 338-349 ◽  
Author(s):  
Przemysław Jaszak ◽  
Konrad Adamek
Keyword(s):  
Stress Distribution ◽  
Experimental Tests ◽  
Numerical Calculations ◽  
Strength Analysis ◽  
Bolted Joint ◽  
Safety Factors ◽  
Good Tool ◽  
Method Of Calculation ◽  
Tightening Force ◽  
Analytical Results

AbstractThe paper presents the method of design and strength analysis of the flange-gasketed-bolted joint. In the first part, analytical calculations were carried out. Their purpose was to determine the assembly torque of nuts to achieve the desired tightness. The flanged joint designated as DN100 PN40 with two different gaskets was taken into consideration. The analytical calculations were performed in accordance with the algorithm included in PN EN 1591-1. In the further step, the numerical calculations were carried out to support the analytical results. The outcome of these calculations were maps of the contact stress distribution on the gasket surface, estimation of safety factors of individual joint elements as well as determination of the flange rotation. Data from the numerical calculations were compared with the analytical results, which confirmed their satisfactory compliance. In the last stage, the experimental tests of the joint were carried out. The main results of the test were the measured values of the leakage level, tightening force of the bolt and estimated safety factors. An indirect result of the experimental measurements were maps of the stress distribution on the contact surface of the gasket, which were determined by means of the measuring film. Ultimately, based on the experimental results, it was found that the proposed analytical method of calculation and simulation of the joint by means of the finite element method was a very good tool for the design of the joint at the required tightness level.

scholarly journals Exploration of Axial Fan Design Space with Data-Driven Approach

2019 ◽  
Vol 4 (2) ◽  
pp. 11
Author(s):  
Gino Angelini ◽  
Alessandro Corsini ◽  
Giovanni Delibra ◽  
Lorenzo Tieghi
Keyword(s):  
Design Space ◽  
Similarity Theory ◽  
Principal Component ◽  
Design Parameters ◽  
Meridional Plane ◽  
Axial Fan ◽  
Axial Fans ◽  
Latent Structures ◽  
And Performance ◽  
Turbomachinery Design

Since the 1960s, turbomachinery design has mainly been based on similarity theory and empirical correlations derived from experimental data and manufacturing experience. Over the years, this knowledge was consolidated and summarized by parameters such as specific speed and diameters that represent the flow features on the meridional plane, hiding however the direct correlations between all the actual design parameters (e.g., blade number or hub-to-tip ratio). Today a series of statistical tools developed for big data analysis sheds new light on correlations among turbomachinery design and performance parameters. In the following article we explore a dataset of over 10,000 axial fans by means of principal component analysis and projection to latent structures. The aim is to find correlations between design and performance features and comment on the capabilities of this approach to give new insights on the design space of axial fans.

Morphing of Reversible Axial Fan Blade: A FSI-FEM Study

2021 ◽  
Author(s):  
Valerio F. Barnabei ◽  
Alessio Castorrini ◽  
Alessandro Corsini ◽  
Franco Rispoli
Keyword(s):  
Research Effort ◽  
Elastic Solid ◽  
Navier Stokes ◽  
Design Solution ◽  
Axial Fan ◽  
Navier Stokes Equation ◽  
Linear Elastic ◽  
Axial Fans ◽  
Fan Blade ◽  
Dynamics Simulations

Abstract Reversible axial fans are widely used in industrial and tunnel ventilation systems, and a lot of research effort is spent in the design process of the blades shape and blades profile. The target is to achieve reasonable performances in both flow directions, but those are still below the levels of the corresponding non-reversible geometries. In this paper, an alternative design solution for reversible axial fan is presented by adopting flexible blades instead of the rigid ones. Such design, inspired by the boat sails, could allow the blade to change its shape by passively adapting to the flow field, from a symmetrical blade profile to a not symmetric one, and thus adapting the curvature to the flow condition. In the paper, a series of alternative materials and material distributions are analysed and compared. The analysis is conducted by performing Fluid-Structure Interaction simulations using stabilized Finite Elements formulations for both the fluid and the structure dynamics. Simulations are performed using the in-house built software FEMpar, which implements the Residual Based Variational MultiScale to model the Navier-Stokes equation, the Total Lagrangian formulation for the non-linear elastic solid and the Solid Extension Moving Mesh Technique to move the fluid mesh.

Surface Coating Effect on Protection of Icing for Axial Fan Blade

2011 ◽  
Author(s):  
Takeshi Murooka ◽  
Shinichirou Shishido ◽  
Riho Hiramoto ◽  
Takakazu Minoya
Keyword(s):  
Surface Coating ◽  
Axial Fan ◽  
Fan Blade

A novel split-belt apparatus: the stress distribution and performance of its tangent split die

2015 ◽  
Vol 35 (3) ◽  
pp. 247-253 ◽  
Author(s):  
Yunfei Yang ◽  
Mingzhe Li ◽  
Bolong Wang ◽  
Zhiwei Liu
Keyword(s):  
Stress Distribution ◽  
And Performance

Strength Analysis of Parallel Grooved Drum

2013 ◽  
Vol 387 ◽  
pp. 115-119
Author(s):  
Qing Zhang ◽  
Kun Zhao ◽  
Ying Yue Xiao ◽  
Xian Rong Qin ◽  
Yuan Tao Sun ◽  
...  
Keyword(s):  
Stress Distribution ◽  
Wall Thickness ◽  
Structure Design ◽  
Strength Analysis ◽  
Design And Optimization ◽  
Simulation Results

Only the basic wall thickness of drum is taken under consideration in traditional parallel grooved drum strength analysis, which is quite conservative for ignoring the thickness of the groove. So in this paper, it is aimed at comparing the strength simulation results for two drum models with and without the thickness of the groove and analyzing the stress distribution of the drum structure, which provides reference for the structure design and optimization of the drum.

Aeroacoustic Optimization of a Pressure-Side Strut Configuration for Subsonic Axial Fans Using Statistical-Empirical Modelling

2018 ◽  
Author(s):  
Igor Neifach ◽  
Gi-Don Na ◽  
Frank Kameier ◽  
Nils Springer ◽  
Marco Wichers
Keyword(s):  
Residential Buildings ◽  
Statistical Design ◽  
Axial Fan ◽  
Noise Emission ◽  
Public Places ◽  
Empirical Modelling ◽  
Passive Construction ◽  
Cooling Fan ◽  
Rotor Stator Interaction ◽  
Axial Fans

This paper deals with the reduction of aerodynamically generated noise in passenger car Cooling-Fan-Modules (CFM), caused by the interaction between the impeller and the downstream-located strut configuration of the axial fan. Even after the car engine is switched off, the fan remains active, as long as cooling is required for certain vehicle components. Especially after a car has been parked in closed parking areas, in close proximity to residential buildings or public places, the noise emission can be a problem. This issue is addressed by dampening the rotor-stator-interaction through passive construction measures. In order to ensure optimal noise reduction, 8 critical design features of the struts are identified and investigated using statistical design of experiment methods (DoE). Based on the results, dedicated insights about the effects of concrete strut features on significant regions of the acoustic fan spectrum are obtained. Furthermore, an optimized strut configuration is derived and metrologically validated using a polyoptimization method. Compared to a current serial baseline configuration, a reduction of the overall sound pressure level by 2.6 dB(A), as well as a reduction of the blade passage frequency tone by 17.6 dB(A) is achieved.

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