scholarly journals Discussion: “Experimental and Analytical Investigation of the Effects of Reynolds Number and Blade Surface Roughness on Multistage Axial Flow Compressors” (Scha¨ffler, A., 1980, ASME J. Eng. Power, 102, pp. 5–12)

1980 ◽  
Vol 102 (1) ◽  
pp. 12-12
Author(s):  
C. C. Koch ◽  
L. H. Smith
Keyword(s):  
Surface Roughness ◽  
Reynolds Number ◽  
Axial Flow ◽  
Analytical Investigation ◽  
Blade Surface ◽  
Axial Flow Compressors

scholarly journals Effect of blade surface roughness on performances of axial flow fans with different blade cambers.

1984 ◽  
Vol 50 (459) ◽  
pp. 2812-2817
Author(s):  
Kenji KANEKO ◽  
Toshiaki SETOGUCHI ◽  
Toshihiro NAKANO ◽  
Masaharu INOUE
Keyword(s):  
Surface Roughness ◽  
Axial Flow ◽  
Blade Surface

Experimental and Analytical Investigation of the Effects of Reynolds Number and Blade Surface Roughness on Multistage Axial Flow Compressors

1980 ◽  
Vol 102 (1) ◽  
pp. 5-12 ◽  
Author(s):  
A. Scha¨ffler
Keyword(s):  
Experimental Data ◽  
Boundary Layer ◽  
Reynolds Number ◽  
Critical Reynolds Number ◽  
Pressure Ratio ◽  
Axial Flow ◽  
Blade Surface ◽  
Laminar Separation ◽  
High Pressure Ratio ◽  
Attached Flow

The general effect of Reynolds Number on axial flow compressors operating over a sufficiently wide range is described and illustrated by experimental data for four multistage axial compressors. The wide operating range of military aircraft engines leads in the back stages of high pressure ratio compression systems to three distinctly different regimes of operation, characterized by the boundary layer conditions of the cascade flow: • laminar separation, • turbulent attached flow with hydraulically smooth blade surface, • turbulent attached flow with hydraulically rough blade surface. Two “critical” Reynolds Numbers are defined, the “lower critical Reynolds Number” below which laminar separation occurs with a definite steepening of the efficiency/Reynolds Number relation and an “upper critical Reynolds Number” above which the blade surface behaves hydraulically rough, resulting in an efficiency independant of Reynolds Number. The permissible blade surface roughness for hydraulically smooth boundary layer conditions in modern high pressure ratio compression systems is derived from experimental data achieved with blades produced by grinding, electrochemical machining and forging. A correlation between the effect of technical roughness and sand type roughness is given. The potential loss of efficiency in the back end of compression systems due to excessive blade roughness is derived from experimental results. The repeatedly experienced different sensitivity of front and back stages towards laminar separation in the low Reynolds Number regime is explained by boundary layer calculations as a Mach Number effect on blade pressure distribution, i.e. transonic versus subsonic flow.

Numerical Investigations on Influence of Uniform Blade Surface Roughness on the Performance Characteristics of a Transonic Axial Flow Compressor Stage

2017 ◽  
Author(s):  
Ravi J. Chotalia ◽  
Dilipkumar Bhanudasji Alone
Keyword(s):  
Surface Roughness ◽  
Steady State ◽  
Axial Flow ◽  
Performance Degradation ◽  
Aviation Industry ◽  
Compressor Stage ◽  
Blade Surface ◽  
Axial Flow Compressor ◽  
Flow Compressor ◽  
The Impact

Application of surface roughness to rotating mechanical bodies will result into performance degradation. In Aviation Industry, one of the most affecting causes for performance or efficiency degradation of gas turbine engine is the blade surface roughness. The aerosols which are very small particles in the atmosphere having diameters in the microns, impinges to the compressor blade inside the aircraft engine at higher altitudes. The aerosols damages surfaces of the compressor blades. Despite of having small dimensions, due to higher velocity of the aircraft, aerosol’s impinging creates roughened surfaces and fouling. This paper is an attempt to numerically evaluate the performance degradation of the single stage transonic axial flow compressor due to uniform roughness created by the aerosols. Various cases with different roughness on various sections of the blades are analyzed to study and identify which section of the blade is more influenced by roughness. The transonic axial flow compressor has a capability of producing 1.36 stage total pressure ratio, swallowing air mass flow rate of 23 kg/s at rated design speed of 12930 rpm is used for the steady state numerical analysis. A systematic steady state 3-dimensional numerical study using solver with SST k-ω turbulence model has been carried out to evaluate the impact of blade surface roughness on the performance of compressor stage. Moreover, cases with the aerosols having different dimensions and their resulting effect is also studied to find out how performance varies when the aircraft enters into atmosphere having big aerosols from the atmosphere having smaller one and vice-e-versa.

Performance Degradation Due to Blade Surface Roughness in a Single-Stage Axial Turbine

2004 ◽  
Author(s):  
Yong Il Yun ◽  
Il Young Park ◽  
Seung Jin Song
Keyword(s):  
Surface Roughness ◽  
Turbine Blades ◽  
Axial Flow ◽  
Suction Side ◽  
Single Stage ◽  
Rotor Blades ◽  
Blade Surface ◽  
Turbine Efficiency ◽  
Order Of Magnitude ◽  
Line Analysis

Turbine blades experience significant surface degradation with service. Previous studies indicate that an order of magnitude or greater increase in roughness height is typical, and these elevated levels of surface roughness significantly influence turbine efficiency and heat transfer. This paper presents measurement and a mean line analysis of turbine efficiency reduction due to blade surface roughness. Performance tests have been conducted in a low speed, single-stage, axial flow turbine with roughened blades. Sheets of sandpaper with equivalent sandgrain roughnesses of 106 and 400 μm have been used to roughen the blades. The roughness heights correspond to foreign deposits on real turbine blades measured by Bons et al. [1]. In the transitionally rough regime (106 μm), normalized efficiency decreases by approximately 4 percent with either roughened stator or roughened rotor and 8 percent with roughness on both the stator and rotor blades. In the fully rough regime (400 μm), normalized efficiency decreases by 2 percent with roughness on the pressure side and by 6 percent with roughness on the suction side. Also, the normalized efficiency decreases by 11 percent with roughness only on stator vanes; 8 percent with roughness only on rotor blades; and 19 percent with roughness on both the stator and rotor blades.

scholarly journals Effect of Blade Surface Roughness on Performances of Axial Flow Fans with Different Blade Cambers

1985 ◽  
Vol 28 (241) ◽  
pp. 1441-1446 ◽  
Author(s):  
Kenji KANEKO ◽  
Toshiaki SETOGUCHI ◽  
Toshihiro NAKANO ◽  
Masahiro INOUE
Keyword(s):  
Surface Roughness ◽  
Axial Flow ◽  
Blade Surface

Performance Degradation due to Blade Surface Roughness in a Single-Stage Axial Turbine

2005 ◽  
Vol 127 (1) ◽  
pp. 137-143 ◽  
Author(s):  
Yong Il Yun ◽  
Il Young Park ◽  
Seung Jin Song
Keyword(s):  
Surface Roughness ◽  
Turbine Blades ◽  
Axial Flow ◽  
Suction Side ◽  
Single Stage ◽  
Rotor Blades ◽  
Blade Surface ◽  
Turbine Efficiency ◽  
Order Of Magnitude ◽  
Line Analysis

Turbine blades experience significant surface degradation with service. Previous studies indicate that an order-of-magnitude or greater increase in roughness height is typical, and these elevated levels of surface roughness significantly influence turbine efficiency and heat transfer. This paper presents measurement and a mean-line analysis of turbine efficiency reduction due to blade surface roughness. Performance tests have been conducted in a low-speed, single-stage, axial flow turbine with roughened blades. Sheets of sandpaper with equivalent sandgrain roughnesses of 106 and 400 μm have been used to roughen the blades. The roughness heights correspond to foreign deposits on real turbine blades measured by Bons et al. [1]. In the transitionally rough regime (106 μm), normalized efficiency decreases by approximately 4% with either roughened stator or roughened rotor and by 8% with roughness on both the stator and rotor blades. In the fully rough regime (400 μm), normalized efficiency decreases by 2% with roughness on the pressure side and by 6% with roughness on the suction side. Also, the normalized efficiency decreases by 11% with roughness only on stator vanes, 8% with roughness only on rotor blades, and 19% with roughness on both the stator and rotor blades.

Numerical Simulation of Gas-Solid Two Phase Flow in Fouled Axial Flow Compressor

2014 ◽  
Author(s):  
Huadong Yang ◽  
Hong Xu
Keyword(s):  
Numerical Simulation ◽  
Surface Roughness ◽  
Two Phase Flow ◽  
Axial Flow ◽  
Particle Mass ◽  
Phase Flow ◽  
Blade Surface ◽  
Two Phase ◽  
Axial Flow Compressor ◽  
Flow Compressor

Particles contained in air can deposit on the blade surface to cause fouling when lubricating oil and water steam are existed. Fouling changes blade geometry and blade surface roughness is increased, thus aerodynamic performance is affected. Many researchers simulated axial flow compressor fouling by adding constant surface roughness and modifying blade thickness which can’t reflect the real status of fouled compressor. In this paper, reverse technology is introduced to reconstruct the solid model of fouled compressor which is imported into fluid flow simulation software. The flow of gas phase and gas-solid coupling phase are implemented to reveal the nature of flow in fouled axial flow compressor. Based on Euler-Lagrange model, this paper made numerical simulation of gas-solid two phase flow in the axial flow compressor rotor cascade. Simulation result shows that fouling causes the decrease of effective flow area, thus thermodynamic performance is degraded. Gas-solid phase flow shows that particles are not uniformly deposited on the blade surface. When particle is smaller and rotor blade is rough, it is more easily deposited on the surface. And particle mass concentration is affected by ambient conditions such as inlet temperature, rotational speed, particle diameter, particle mass flow rate.

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