Predicting Blade Leading Edge Erosion in an Axial Induced Draft Fan

2012 ◽  
Vol 134 (4) ◽  
Author(s):  
Alessandro Corsini ◽  
Andrea Marchegiani ◽  
Franco Rispoli ◽  
Paolo Venturini ◽  
Anthony G. Sheard
Keyword(s):  
Numerical Study ◽  
Fluid Dynamic ◽  
Leading Edge ◽  
Combustion Products ◽  
Aerodynamic Performance ◽  
Interpolation Scheme ◽  
Axial Fan ◽  
Critical Limit ◽  
Induced Draft Fan ◽  
Blade Leading Edge

Induced draft fans extract coal fired boiler combustion products, including particles of un-burnt coal and ash. As a consequence of the particles, the axial fan blades’ leading edges are subject to erosion. Erosion results in the loss of the blade leading edge aerodynamic profile and a reduction of blade chord and effective camber that together degrade aerodynamic performance. An experimental study demonstrated that while the degradation of aerodynamic performance begins gradually, it collapses as blade erosion reaches a critical limit. This paper presents a numerical study on the evolution of blade leading edge erosion patterns in an axial induced draft fan. The authors calculated particle trajectories using an in-house computational fluid dynamic (CFD) solver coupled with a trajectory predicting solver based on an original finite element interpolation scheme. The numerical study clarifies the influence of flow structure, initial blade geometry, particle size, and concentration on erosion pattern.

On the Role of Leading-Edge Bumps in the Control of Stall Onset in Axial Fan Blades

2013 ◽  
Vol 135 (8) ◽  
Author(s):  
Alessandro Corsini ◽  
Giovanni Delibra ◽  
Anthony G. Sheard
Keyword(s):  
Numerical Study ◽  
Fluid Dynamic ◽  
Three Dimensional ◽  
Leading Edge ◽  
Suction Side ◽  
Axial Fan ◽  
Early Recovery ◽  
Viscosity Models ◽  
Flow Mechanisms ◽  
The Impact

Taking a lead from the humpback whale flukes, characterized by a series of bumps that result in a sinusoidal-like leading edge, this paper reports on a three-dimensional numerical study of sinusoidal leading edges on cambered airfoil profiles. The turbulent flow around the cambered airfoil with the sinusoidal leading edge was computed at different angles of attack with the open source solver OpenFOAM, using two different eddy viscosity models integrated to the wall. The reported research focused on the effects of the modified leading edge in terms of lift-to-drag performance and the influence of camber on such parameters. For these reasons a comparison with a symmetric airfoil is provided. The research was primarily concerned with the elucidation of the fluid flow mechanisms induced by the bumps and the impact of those mechanisms on airfoil performance, on both symmetric and cambered profiles. The bumps on the leading edge influenced the aerodynamic performance of the airfoil, and the lift curves were found to feature an early recovery in post-stall for the symmetric profile with an additional gain in lift for the cambered profile. The bumps drove the fluid dynamic on the suction side of the airfoil, which in turn resulted in the capability to control the separation at the trailing edge in coincidence with the peak of the sinusoid at the leading edge.

A study of fan-distortion interaction within the fan rotor

2020 ◽  
pp. 095765092092004
Author(s):  
Zhihui Li ◽  
Juan Du ◽  
Qianfeng Zhang ◽  
Guofeng Ji ◽  
Hongwu Zhang
Keyword(s):  
High Performance ◽  
Fluid Dynamic ◽  
Three Dimensional ◽  
Leading Edge ◽  
Aerodynamic Performance ◽  
Stagnation Pressure ◽  
Detached Eddy Simulation ◽  
Axial Fan ◽  
Fan Performance ◽  
Inlet Distortion

Boundary-layer-ingesting fans and compressors in the next-generation turbofan engines require high-performance operations under distorted inflow. The aim of this work is to study the effects of inlet distortions including inlet stagnation pressure and temperature distortion, on the aerodynamic performance of a transonic axial fan. Firstly, the validated full-annulus, unsteady, three-dimensional computational fluid dynamic code in conjunction with detached Eddy simulation approach is used here to simulate the fan flows assembly with individual inlet stagnation pressure/temperature distortion. Then, the propagation process of the inlet distortion waves is analyzed to understand how the aerodynamic performance degradation is triggered. The simulation results show that the fan performance is remarkably degraded when the inlet distortion is introduced. The leading-edge spillage, the trailing edge back flow and the “tornado vortex” occur when parts of fan blades encounter the incoming distorted flows. Finally, the responses of fan to the combined inlet stagnation distortion effects are discussed in this paper. It is found that the combined distortion effects can be predicted based on the sum of the performance responses to the individual constituent distortions. Furthermore, the relative location of the constituent distortions shows a non-ignorable influence on the overall fan performance, especially for the intensified inlet distortion.

scholarly journals Experimental and numerical study on the performance of an axial fan with a Gurney flap

2018 ◽  
Vol 10 (10) ◽  
pp. 168781401880380 ◽  
Author(s):  
Liu Chen ◽  
Haijun Xie ◽  
Jun Xu ◽  
Ren Dai ◽  
Jian Chen
Keyword(s):  
Computational Fluid Dynamic ◽  
Numerical Study ◽  
Fluid Dynamic ◽  
Pressure Rise ◽  
Field Analysis ◽  
Horizontal Wind ◽  
Tip Leakage Flow ◽  
Axial Fan ◽  
Gurney Flap ◽  
Lift Enhancement

Gurney flap is a miniature lift-enhancement device installed at the airfoil trailing edge and has been successfully applied to fixed wing aircraft and low-speed horizontal wind turbines. In this article, Gurney flap is extended to increase pressure output of a diffusive cascade flow in rotating turbomachinery, which is complicated for its three dimensionalities and diffusive separation characteristics. Wind tunnel tests and computational fluid dynamic simulations were accomplished on an axial fan profiled with an NACA 65-(12)10 airfoil to investigate the effects of Gurney flap on the performance of a high solidity. We present the detailed flow features of the fan with and without Gurney flap after validating the simulation results with the experimental datum. The experimental results show positive Gurney flap effects on fan’s pressure rise and flow rate improvement. However, negative Gurney flap effects on fan’s efficiency are more evident than Gurney flap on isolated airfoils. Detailed flow field analysis from computational fluid dynamic computation reveals that the increased airfoil pressure loading along the fan blade chord strengthens the tip leakage flow, which induces more tip second flow losses than in the baseline fan. In addition to the positive lift enhancement, the net Gurney flap effect in diffusion cascade is influenced by the three-dimensional flow structure.

scholarly journals Numerical Analysis of Effect of Leading-Edge Rotating Cylinder on NACA0021 Symmetric Airfoil

2019 ◽  
Vol 4 (7) ◽  
pp. 11-17
Author(s):  
Md. Abdus Salam ◽  
Vikram Deshpande ◽  
Nafiz Ahmed Khan ◽  
M. A. Taher Ali
Keyword(s):  
Free Stream ◽  
Numerical Study ◽  
Tangential Velocity ◽  
Leading Edge ◽  
Rotating Cylinder ◽  
Aerodynamic Performance ◽  
Stream Velocity ◽  
Surface Boundary ◽  
Lower Velocity ◽  
Numerical Studies

The moving surface boundary control (MSBC) has been a Centre stage study for last 2-3 decades. The preliminary aim of the study was to ascertain whether the concept can improve the airfoil characteristics. Number of experimental and numerical studies pointed out that the MSBC can superiorly enhance the airfoil performance albeit for higher velocity ratios (i.e. cylinder tangential velocity to free stream velocity). Although abundant research has been undertaken in this area on different airfoil performances but no attempt was seen to study effect of MSBC on NACA0021 airfoil for and also effects of lower velocity ratios. Thus, present paper focusses on numerical study of modified NACA 0021 airfoil with leading edge rotating cylinder for velocity ratios (i.e.) between 1 to 1.78 at different angles of attack. The numerical study indicates that the modified airfoil possess better aerodynamic performance than the base airfoil even at lower velocity ratios (i.e. for velocity ratios 0.356 and beyond). The study also focusses on reason for improvement in aerodynamic performance by close look at various parameters.

Effect of Tubercles Shape on the Aerodynamic Performance of a Wind Turbine Blade Operating at Low Reynolds Number

2019 ◽  
Author(s):  
D. S. Swasthika ◽  
Mahesh K. Varpe
Keyword(s):  
Reynolds Number ◽  
Wind Turbine ◽  
Turbine Blade ◽  
Leading Edge ◽  
Aerodynamic Performance ◽  
Vital Role ◽  
Wind Turbine Blade ◽  
Geometric Parameters ◽  
Different Types ◽  
Blade Leading Edge

Abstract In wind turbine blade, most of the losses occurs due to aerodynamic losses in the post stall operating condition. Adoption of the blade leading edge tubercles improves the post stall aerodynamic performance. Nevertheless the geometric parameters of the protuberance play a vital role in influencing the aerodynamic performance, it is possible that shape of the protuberance may also have aerodynamic significance. In this paper different types of tubercle shapes are adopted on the blade leading edge to study the improvement in the aerodynamic performance. Each of the shape is studied for different AOA operating at Reynolds number of 3 × 105. The results revealed that the shape of the tubercles also influence the flow which affects the performances.

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