The Influence of the Blading Surface Roughness on the Aerodynamic Behavior and Characteristic of an Axial Compressor

1980 ◽  
Vol 102 (2) ◽  
pp. 283-287 ◽  
Author(s):  
K. Bammert ◽  
G. U. Woelk
Keyword(s):  
Surface Roughness ◽  
Surface Quality ◽  
Flow Rate ◽  
Pressure Ratio ◽  
Axial Compressor ◽  
Low Flow ◽  
Blade Surface ◽  
Characteristic Curves ◽  
Flow Losses

The conversion of energy in an axial compressor is influenced in great measure by the surface quality of the blading. To achieve low flow losses, the roughness values of the blade surface must be below certain limits. However, the blade surface, which is hydraulically smooth on commissioning of the machine, is in many cases attacked by dirt, corrosion and erosion during operation. For investigation of the influence of the surface quality on the efficiency, flow rate, pressure ratio, and the shifting of the characteristic curves, systematic measurements were taken on a three-stage axial compressor with smooth and uniformly rough blading. The roughness was produced by applying loose emery grain of different grades.

Electrostatic high-velocity solid lubricant machining system for performance improvement of turning Ti–6Al–4V alloy

2017 ◽  
Vol 233 (1) ◽  
pp. 118-131 ◽  
Author(s):  
Rakesh Kumar Gunda ◽  
Suresh Kumar Reddy Narala
Keyword(s):  
Tool Wear ◽  
Surface Quality ◽  
Tool Life ◽  
Flow Rate ◽  
High Velocity ◽  
Solid Lubricant ◽  
Machining Process ◽  
Low Flow ◽  
Minimum Quantity

In any machining operation, a major division of energy is converted into heat which creates detrimental effects on tool wear, tool life and surface quality of machined work material. Effective cooling/lubrication in the machining zone is essential to improve friction and temperatures by efficient heat dissipation which increases tool life and surface quality. But adverse health effects caused by use of flood cooling are drawing manufacturers’ attention to develop methods for controlling occupational exposure to cutting fluids. In demanding the improvement of productivity and product quality of machining, use of solid lubricant thin film was suggested as one of the necessary alternative machining techniques to apply lubricants effectively to the high-temperature zone. There is a general concern in the machining process in terms of applying lubricants effectively to the machining zone. Therefore, this research work contributes to the development of a novel approach to apply lubricants effectively to the rake face and flank face of the cutting tool without polluting the environment. Electrostatic high-velocity solid lubricant assisted machining is a novel technique used in the machining process with a very low flow rate (1–20 mL/h) to enhance the process performance of turning difficult-to-cut materials. The performance of electrostatic high-velocity solid lubricant technique is studied in comparison to minimum quantity solid lubricant, minimum quantity lubricant and dry and wet (flood cooling) to assess the performance considering surface roughness, cutting force and tool wear as performance indices. The experimental results revealed that electrostatic high-velocity solid lubricant with MoS2 solid lubricant at low volume and constant flow rate has observed high potential to apply lubricants effectively in the machining zone when compared with the considered environmental conditions. This work is expected to form a scientific basis toward developing electrostatic high-velocity solid lubricant technique for reducing the manufacturing impact in the machining of aerospace components such as Ti–6Al–4V alloy in terms of both machinability and environmental perspectives.

Recent Development of the Aero-Engine Impeller and Blade Surface Polishing Technology

2010 ◽  
Vol 135 ◽  
pp. 7-12 ◽  
Author(s):  
Hang Gao ◽  
Z. Zhao ◽  
Y.W. Sun
Keyword(s):  
Surface Roughness ◽  
Weight Ratio ◽  
Low Flow ◽  
Blade Surface ◽  
Flow Losses ◽  
Surface Polishing ◽  
Finishing Process ◽  
Aero Engine ◽  
Recent Developments ◽  
Micro Morphology

The air compressing efficiency and heat conductance of aero-engine is markedly influenced by the surface micro-morphology and surface roughness of the impeller and blades, which will further affect the thrust weight ratio of plane. To achieve low flow losses, the roughness values of the impeller and blade surface must be below certain limits. Some polishing techniques as final finishing process of the impeller and blades are reviewed and their recent developments are shown in the paper. Further more a new kind of point-by-point NC polishing principle for aero-engine impeller surface, in which surface roughness will gradually change from the inlet to the outlet, are presented.

scholarly journals The blade surface performance and its robotic machining

2020 ◽  
Vol 17 (2) ◽  
pp. 172988142091409
Author(s):  
Lei Qiu ◽  
Liangtao Qi ◽  
Lanlan Liu ◽  
Zhu Zhang ◽  
Jianwei Xu
Keyword(s):  
Surface Roughness ◽  
Surface Quality ◽  
Great Influence ◽  
Blade Surface ◽  
Core Content ◽  
Negative Effect ◽  
Surface Performance ◽  
Different Characteristics ◽  
Positive Effect

Through numerical calculations, it could be found that when the blade surface quality reaches a certain level, the surface quality of the blade was continuously improved, and the guarantee effect on its performance would be weakened. Under this circumstance, continuing to improve the surface quality of the blade had no positive effect on the performance of the blade. Studies had shown that when the blade surface equivalent grit roughness Ks reaches 4.96 (about R a = 0.8 µm), the blade performance was close to the smooth surface of the blade, and no further processing was required to improve the surface roughness. When the surface equivalent grit Ks was greater than 4.96 µm, the surface roughness had a great influence on the blade performance. When Ks was larger than 40 µm, the negative effect is significantly increased. For the different characteristics of the blade and different processing conditions, four kinds of robot-based blade surface grinding schemes were proposed, of which the core content was the robot layout. Based on the robot group’s fitting to the spatial surface and the path planning, the experimental verification was carried out.

Observation in the Surface Roughness of Silicon Wafer during Semi-Fixed Abrasive Machining with Large Grains

2009 ◽  
Vol 69-70 ◽  
pp. 253-257
Author(s):  
Ping Zhao ◽  
Jia Jie Chen ◽  
Fan Yang ◽  
K.F. Tang ◽  
Ju Long Yuan ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Surface Quality ◽  
Silicon Wafer ◽  
Processing Parameters ◽  
Wafer Surface ◽  
Abrasive Machining ◽  
Fixed Abrasive ◽  
Is Failure ◽  
Better Than

Semi-fixed abrasive is a novel abrasive. It has a ‘trap’ effect on the hard large grains that can prevent defect effectively on the surface of the workpiece which is caused by large grains. In this paper, some relevant experiments towards silicon wafers are carried out under the different processing parameters on the semi-fixed abrasive plates, and 180# SiC is used as large grains. The processed workpieces’ surface roughness Rv are measured. The experimental results show that the surface quality of wafer will be worse because of higher load and faster rotating velocity. And it can make a conclusion that the higher proportion of bond of the plate, the weaker of the ‘trap’ effect it has. Furthermore the wet environment is better than dry for the wafer surface in machining. The practice shows that the ‘trap’ effect is failure when the workpiece is machined by abrasive plate which is 4.5wt% proportion of bond in dry lapping.

The mechanism of process parameters influencing the AlSi10Mg side surface quality fabricated via laser powder bed fusion

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Shimin Dai ◽  
Hailong Liao ◽  
Haihong Zhu ◽  
Xiaoyan Zeng
Keyword(s):  
Surface Roughness ◽  
Surface Quality ◽  
Process Parameters ◽  
Laser Power ◽  
Side Surface ◽  
Laser Powder Bed Fusion ◽  
Scanning Velocity ◽  
Content Type ◽  
Powder Bed

Purpose For the laser powder bed fusion (L-PBF) technology, the side surface quality is essentially important for industrial applicated parts, such as the inner flow parts. Contour is generally adopted at the parts’ outline to enhance the side surface quality. However, the side surface roughness (Ra) is still larger than 10 microns even with contour in previous studies. The purpose of this paper is to study the influence of contour process parameters, laser power and scanning velocity on the side surface quality of the AlSi10Mg sample. Design/methodology/approach Using L-PBF technology to manufacture AlSi10Mg samples under different contour process parameters, use a laser confocal microscope to capture the surface information of the samples, and obtain the surface roughness Ra and the maximum surface height Rz of each sample after analysis and processing. Findings The results show that the side surface roughness decreases with the increase of the laser power at the fixed scanning velocity of 1,000 mm/s, the side surface roughness Ra stays within the error range as the contour velocity increases. It is found that the Ra increases with the scanning velocity increasing and the greater the laser power with the greater Ra increases when the laser power of contour process parameters is 300 W, 350 W and 400 W. The Rz maintain growth with the contour scanning velocity increasing at constant laser power. The continuous uniform contour covers the pores in the molten pool of the sample edge and thus increase the density of the sample. Two mechanisms named “Active adhesion” and “Passive adhesion” cause sticky powder. Originality/value Formation of a uniform and even contour track is key to obtain the good side surface quality. The side surface quality is determined by the uniformity and stability of the contour track when the layer thickness is fixed. These research results can provide helpful guidance to improve the surface quality of L-PBF manufactured parts.

Investigation of the Effects of Technological Parameters on Surface Roughness in Extrusion Bars of Aluminum Alloy

2019 ◽  
Vol 889 ◽  
pp. 155-160
Author(s):  
Trong Mai Nguyen ◽  
Đuc Quy Tran ◽  
Van Nghe Pham ◽  
Van Canh Nguyen
Keyword(s):  
Surface Roughness ◽  
Aluminum Alloy ◽  
Surface Quality ◽  
Research Work ◽  
Extrusion Process ◽  
Optimal Parameters ◽  
Technological Parameters

In this research work, the result of the effects of technological parameters on surface roughness in extrusion bars of aluminum alloy were pesented. The results of this study may be used for choosing optimal parameters of extrusion process so that surface quality of extruded bar was improved.

scholarly journals Impact of Structural Defects on the Surface Quality of Hardwood Species Sliced Veneers

2020 ◽  
Vol 10 (18) ◽  
pp. 6265
Author(s):  
Vasiliki Kamperidou ◽  
Efstratios Aidinidis ◽  
Ioannis Barboutis
Keyword(s):  
Surface Roughness ◽  
Surface Quality ◽  
Wood Species ◽  
Research Work ◽  
Structural Defects ◽  
Material Surface ◽  
Typical Structure ◽  
Hardwood Species ◽  
The Impact

The surface roughness constitutes one of the most critical properties of wood and wood veneers for their extended utilization, affecting the bonding ability of the veneers with one another in the manufacturing of wood composites, the finishing, coating and preservation processes, and the appearance and texture of the material surface. In this research work, logs of five significant European hardwood species (oak, chestnut, ash, poplar, cherry) of Balkan origin were sliced into decorative veneers. Their surface roughness was examined by applying a stylus tracing method, on typical wood structure areas of each wood species, as well as around the areas of wood defects (knots, decay, annual rings irregularities, etc.), to compare them and assess the impact of the defects on the surface quality of veneers. The chestnut veneers presented the smoothest surfaces, while ash veneers, despite the higher density, recorded the highest roughness. In most of the cases, the roughness was found to be significantly lower around the defects, compared to the typical structure surfaces, probably due to lower porosity, higher density and the presence of tensile wood. The results reveal that the presence of defects does not affect the roughness of the veneers and increases neither the processing requirements of the veneer sheets before finishing, nor the respective production cost of veneers and the veneer-based wood panels. The high utilization prospects of the examined wood species in veneer production, even those bearing various defects, is highlighted.

scholarly journals Surface Roughness Investigation of Poly-Jet 3D Printing

Mathematics ◽  
2020 ◽  
Vol 8 (10) ◽  
pp. 1758
Author(s):  
Nectarios Vidakis ◽  
Markos Petousis ◽  
Nikolaos Vaxevanidis ◽  
John Kechagias
Keyword(s):  
Surface Roughness ◽  
3D Printing ◽  
Surface Quality ◽  
Back Propagation ◽  
Physical Models ◽  
Layer By Layer ◽  
Linear Regression Models ◽  
Feed Forward Back Propagation ◽  
The Impact

An experimental investigation of the surface quality of the Poly-Jet 3D printing (PJ-3DP) process is presented. PJ-3DP is an additive manufacturing process, which uses jetted photopolymer droplets, which are immediately cured with ultraviolet lamps, to build physical models, layer-by-layer. This method is fast and accurate due to the mechanism it uses for the deposition of layers as well as the 16 microns of layer thickness used. Τo characterize the surface quality of PJ-3DP printed parts, an experiment was designed and the results were analyzed to identify the impact of the deposition angle and blade mechanism motion onto the surface roughness. First, linear regression models were extracted for the prediction of surface quality parameters, such as the average surface roughness (Ra) and the total height of the profile (Rt) in the X and Y directions. Then, a Feed Forward Back Propagation Neural Network (FFBP-NN) was proposed for increasing the prediction performance of the surface roughness parameters Ra and Rt. These two models were compared with the reported ones in the literature; it was revealed that both performed better, leading to more accurate surface roughness predictions, whilst the NN model resulted in the best predictions, in particular for the Ra parameter.

scholarly journals Rotary Ultrasonic Machining of Alumina Ceramic: An Experimental Investigation of Tool Path and Tool Overlapping

2020 ◽  
Vol 10 (5) ◽  
pp. 1667 ◽  
Author(s):  
Basem M. A. Abdo ◽  
Abdualziz El-Tamimi ◽  
Emad Abouel Nasr
Keyword(s):  
Surface Roughness ◽  
Surface Morphology ◽  
Surface Quality ◽  
Tool Path ◽  
Removal Rate ◽  
Ultrasonic Machining ◽  
Rotary Ultrasonic Machining ◽  
Roughness Surface ◽  
Tool Wear Mechanisms

Pocket milling has been regarded as one of the most widely used operations in machining. The surface quality of the machined pockets is an essential aspect of any engineering and medical applications. In the current study, rotary ultrasonic machining (RUM) was applied for milling micro-pockets on alumina (Al2O3) ceramic. The objective of this research was to analyze the effect of the tool overlapping parameters on the surface roughness, surface morphology and the profiles of the machined pockets. Subsequently, the effect of different tool path strategies was analyzed on the surface quality and the material removal rate (MRR) of the machined pockets. A scanning electron microscope is used for analyzing the tool wear mechanisms. The experimental results provide evidence that the surface roughness, surface morphology and the MRR have been significantly affected by the considered tool overlapping and the tool path strategies. Furthermore, among the selected tool overlapping parameters (5–25%) and the tool path strategies, the best surface roughness (Ra = 0.155 μm and Rt = 1.432 µm) of the machined pockets can be found at 20% of the tool overlapping with a mix of uni-directional and zigzag tool path strategy.

ANALYSIS OF THE CORRELATION BETWEEN FRACTAL STRUCTURE OF CUTTING FORCE SIGNAL AND SURFACE ROUGHNESS OF MACHINED WORKPIECE IN END MILLING OPERATION

Fractals ◽  
2019 ◽  
Vol 27 (02) ◽  
pp. 1950013 ◽  
Author(s):  
AHMAD THUFFAIL THASTHAKEER ◽  
ALI AKHAVAN FARID ◽  
CHANG TECK SENG ◽  
HAMIDREZA NAMAZI
Keyword(s):  
Surface Roughness ◽  
Cutting Force ◽  
Surface Quality ◽  
Cutting Forces ◽  
End Milling ◽  
Complex Structure ◽  
Machined Surface ◽  
End Mills ◽  
Machining Operations

Analysis of the machined surface is one of the major issues in machining operations. On the other hand, investigating about the variations of cutting forces in machining operation has great importance. Since variations of cutting forces affect the surface quality of machined workpiece, therefore, analysis of the correlation between cutting forces and surface roughness of machined workpiece is very important. In this paper, we employ fractal analysis in order to investigate about the complex structure of cutting forces and relate them to the surface quality of machined workpiece. The experiments have been conducted in different conditions that were selected based on cutting depths, type of cutting tool (serrated versus. square end mills) and machining conditions (wet and dry machining). The result of analysis showed that among all comparisons, we could only see the correlation between complex structure of cutting force and the surface roughness of machined workpiece in case of using serrated end mill in wet machining condition. The employed methodology in this research can be widely applied to other types of machining operations to analyze the effect of variations of different parameters on variability of cutting forces and surface roughness of machined workpiece and then investigate about their correlation.

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