scholarly journals A Prediction Method for the Frictional Torque of a Rotating Disk in a Stationary Housing With Superimposed Radial Outflow

1997 ◽  
Author(s):  
W. Gärtner
Keyword(s):  
Experimental Data ◽  
Governing Equation ◽  
Prediction Method ◽  
Rotating Disk ◽  
Frictional Torque ◽  
Engineering Practice ◽  
Axial Distance ◽  
New Correlation ◽  
Radial Outflow ◽  
Spread Sheet

Experimental data from various sources for the frictional torque of a rotating disk in a stationary housing under the influence of a superimposed radial outflow were correlated. Existing correlations were found to overpredict the frictional torque when the superimposed flow exceeds the pumped flow of the rotating disk. Therefore a new correlation is established for this case to improve the agreement with experimental results. Since the governing equation is an integral which can only be solved numerically the method is installed in a PC-based spread sheet programme for convenient use in the engineering practice. For throughflow rates less or equal than the pumped flow of the rotating disk an existing correlation is modified to take account of the effect on the frictional torque of the axial distance between the disk and the stationary housing.

scholarly journals A Momentum Integral Method to Predict the Frictional Torque of a Rotating Disk With Protruding Bolts

1998 ◽  
Author(s):  
W. Gärtner
Keyword(s):  
Experimental Data ◽  
Boundary Layer ◽  
Integral Equations ◽  
Critical Review ◽  
Integral Method ◽  
Rotating Disk ◽  
Frictional Torque ◽  
Momentum Integral ◽  
Good Agreement

A momentum integral method was developed to predict the frictional torque of a disk rotating in quiescent air with cylindrical protrusions mounted on its surface. The predicted torque is compared to experimental data taken for the protrusions placed on two different radii on the disk with two different numbers of protrusions on each radius. A critical review of the calculated results reveals that caused by the protrusions the predicted thickness of the boundary layer on the disk is of the same magnitude as the radius of the disk. Since in this case Prandtl’s simplifications for the boundary layer on which the momentum integral equations are based upon are not valid their use appears to be doubtful. However, the predicted frictional torque is in good agreement with the measurements for all configurations tested except for that with the smallest circumferential distance between the protrusions where the torque is overpredicted by the method. The application of the method for a disk rotating in a stationary housing is briefly discussed.

Land Subsidence Prediction Method of Power Cables Pipe Jacking Based on the Peck Theory

2013 ◽  
Vol 634-638 ◽  
pp. 3721-3724
Author(s):  
Yuan Liang Zhang ◽  
Yi Hu Zhang
Keyword(s):  
Land Subsidence ◽  
Prediction Method ◽  
Dominant Factor ◽  
Engineering Practice ◽  
Foundation Settlement ◽  
Power Cables ◽  
Overhead Transmission Line ◽  
Allowable Range ◽  
Calculation Results ◽  
Range Calculation

Overhead transmission line and cable are generally used for across or crossing the railway, highways and rivers.For higher deformation requirement of operation of the railway and highway foundation settlement,to ensure that the cable through the process of foundation in regulating the allowable range, calculation and prediction of foundation settlement is specially necessary.Based on the Peck theory, the dominant factor in foundation settlement-strata loss calculation method is introduced supplemented with measured settlement observation records in this paper,which confirmes that the calculation results are replicab in engineering practice.

A correlation to predict the performance characteristics of centrifugal pumps handling slurries

1997 ◽  
Vol 211 (2) ◽  
pp. 147-157 ◽  
Author(s):  
K A Kazim ◽  
B Maiti ◽  
P Chand
Keyword(s):  
Experimental Data ◽  
Particle Size ◽  
Suspended Solids ◽  
Reduction Factor ◽  
Performance Characteristics ◽  
Centrifugal Pumps ◽  
Pump Performance ◽  
New Correlation ◽  
Effect Of Particle Size ◽  
The Individual

Centrifugal pumps are being used increasingly for transportation of slurries through pipelines. To design a slurry handling system it is essential to have a knowledge of the effects of suspended solids on the pump performance. A new correlation to predict the head reduction factor for centrifugal pumps handling solids has been developed. This correlation takes into account the individual effect of particle size, particle size distribution, specific gravity and concentration of solids on the centrifugal pump performance characteristics. The range of validity of the correlation has been verified by experiment and by using experimental data available from the literature. The present correlation shows better agreement with the experimental data than existing correlations.

An Implicit Off-Design Deviation Angle Correlation of Axial Flow Compressor Blade Elements

2017 ◽  
Author(s):  
Wu Dong-run ◽  
Teng Jin-fang ◽  
Qiang Xiao-qing ◽  
Feng Jin-zhang
Keyword(s):  
Experimental Data ◽  
Incidence Angle ◽  
High Reliability ◽  
Axial Flow ◽  
Compressor Blade ◽  
Deviation Angle ◽  
Axial Flow Compressor ◽  
New Correlation ◽  
Classical Correlations ◽  
Flow Compressor

This paper applies a new analytical/empirical method to formulate the off-design deviation angle correlation of axial flow compressor blade elements. An implicit function of deviation angle is used to map off-design deviation curves into linear correlations (minimum linear correlation coefficient R = 0.959 in this paper). Solution of the coefficients in the correlation is given through the study of classical theories and statistical analysis of the experimental data. The off-design deviation angle can be calculated numerically. The approach requires only knowledge of the blade element geometry. The comparison among 2 classical correlations and the new correlation proposed in this paper shows the new correlation has minimum error over the entire range of incidence angle while classical correlations show high reliability only in a limited range. Experimental data in this paper is collected from NASA’s open technical reports. Rotors and stators are studied together. Considering there is significant deviation angle variation along spanwise direction, only data at 50% span is studied, if possible. The error among experimental data, statistical regressions of the experimental data, and numerical results based on the new correlation is discussed. It has to be noted that the influence of the flow condition other than incidence angle is only being discussed but with less break through.

Pressure, Frictional Resistance, and Flow Characteristics of the Partially Wetted Rotating Disk

1968 ◽  
Vol 90 (2) ◽  
pp. 395-404 ◽  
Author(s):  
H. N. Ketola ◽  
J. M. McGrew
Keyword(s):  
Experimental Data ◽  
Reynolds Number ◽  
Pressure Gradient ◽  
Flow Characteristics ◽  
Frictional Resistance ◽  
Rotating Disk ◽  
Practical Applications ◽  
Stationary Wall ◽  
Spacing Ratio ◽  
Analytical Expressions

A theory of the partially wetted rotating disk is described and experimental data presented which verify the application of this theory in practical applications. Four different flow regimes may be identified according to the value of the disk Reynolds number and the spacing ratio between the disk and stationary wall. The analytical expressions for prediction of the pressure gradient developed and the frictional resistance are uniquely determined by the disk Reynolds number, spacing ratio, and the degree of wetting of the disk.

scholarly journals Conditions of equivalence of effects for the solid body from incompressible material

2018 ◽  
Vol 196 ◽  
pp. 01031 ◽  
Author(s):  
Elephan Agakhanov ◽  
Murad Agakhanov ◽  
Lyudmila Sultanova ◽  
Zabiya Hizriyeva
Keyword(s):  
Solid Body ◽  
Design Research ◽  
Rotating Disk ◽  
Experimental Methods ◽  
Incompressible Material ◽  
Engineering Practice ◽  
General View ◽  
Deformable Solid ◽  
Special Cases ◽  
Deformable Solid Body

Polemicizing with the existing opinion that modern numerical methods allow to solve practically any problem of mechanics, it should be noted that analytical and experimental methods still are relevant, and a complex of methods leads to development of mechanics of a deformable solid body. At present one of the most important directions of development of mechanics of a deformable solid body is creation of the approaches that allow to combine organically great computing opportunities of modern supercomputers with experimental methods of the material and design research. In engineering practice at production of designs and products incompressible materials are widely used. Assessment of their durability requires detailed studying of deflected mode caused by action of various loadings and forces. For a solid body from incompressible material, using the resolving equations set of mechanics of a deformable solid body, at action of the compelled deformations of a general view, volume and superficial forces conditions of equivalence are established. It is shown that the known solutions are special cases of the established equivalence conditions. The efficiency of the analytical solution of a three-dimensional task on the rotating disk from incompressible material is shown by the method of equivalence of effects.

scholarly journals Structural Damage Detection Based on Real-Time Vibration Signal and Convolutional Neural Network

2020 ◽  
Vol 10 (14) ◽  
pp. 4720 ◽  
Author(s):  
Zhiqiang Teng ◽  
Shuai Teng ◽  
Jiqiao Zhang ◽  
Gongfa Chen ◽  
Fangsen Cui
Keyword(s):  
Neural Network ◽  
Experimental Data ◽  
Convolutional Neural Network ◽  
Real Time ◽  
Structural State ◽  
Detection Method ◽  
Steel Frame ◽  
Engineering Practice ◽  
Detection Accuracy ◽  
Vibration Signals

The traditional methods of structural health monitoring (SHM) have obvious disadvantages such as being time-consuming, laborious and non-synchronizing, and so on. This paper presents a novel and efficient approach to detect structural damages from real-time vibration signals via a convolutional neural network (CNN). As vibration signals (acceleration) reflect the structural response to the changes of the structural state, hence, a CNN, as a classifier, can map vibration signals to the structural state and detect structural damages. As it is difficult to obtain enough damage samples in practical engineering, finite element analysis (FEA) provides an alternative solution to this problem. In this paper, training samples for the CNN are obtained using FEA of a steel frame, and the effectiveness of the proposed detection method is evaluated by inputting the experimental data into the CNN. The results indicate that, the detection accuracy of the CNN trained using FEA data reaches 94% for damages introduced in the numerical model and 90% for damages in the real steel frame. It is demonstrated that the CNN has an ideal detection effect for both single damage and multiple damages. The combination of FEA and experimental data provides enough training and testing samples for the CNN, which improves the practicability of the CNN-based detection method in engineering practice.

Real-Time Prediction Method for Performance Degradation Trend Based on Reliability Experimental Data

2013 ◽  
Vol 321-324 ◽  
pp. 757-761 ◽  
Author(s):  
Chen Liang Song ◽  
Zhen Liu ◽  
Bin Long ◽  
Cheng Lin Yang
Keyword(s):  
Experimental Data ◽  
Real Time ◽  
Field Data ◽  
Prediction Method ◽  
Field Method ◽  
Performance Degradation ◽  
New Method ◽  
Time Prediction ◽  
Prediction Result ◽  
The Relationship

According to the real-time prediction for performance degradation trend, the commonly used method is just based on field data. But this methods prediction result will not be so much ideal when the fitting of degradation trend of field data is not good. To solve the problem, the paper introduces a new method which is not only based on field method but also based on reliability experimental data coming from the history experiment. We use the relationship between the field data and reliability experimental data to get the result of the two kinds of data respectively and then get the weights according to the two prediction results. Finally, the final real-time prediction result for performance degradation tendency can obtain by allocating the weights to the two prediction results.

Spin Coating Planarization Of Integrated Circuit Topography On A Rotating Disk

1991 ◽  
Vol 227 ◽  
Author(s):  
Roger K. Yonkoski ◽  
David S. Soane
Keyword(s):  
Experimental Data ◽  
Fluid Flow ◽  
Integrated Circuit ◽  
Spin Coating ◽  
Rotating Disk ◽  
Momentum Conservation ◽  
Flat Surfaces ◽  
Determination Of Parameters ◽  
Polyimide Precursor

ABSTRACTPolyimide is commonly used in the microelectronic industry for interconnection applications because of its ability to planarize features typically found on an IC chip. A mathematical model is developed to describe fluid flow on a rotating disk based on the principles of mass and momentum conservation. Constitutive relationships necessary for this model are proposed. Experimental data for polyimide precursor solutions are presented which enable the determination of parameters for the constitutive equations. This model is used to describe the film profiles over flat surfaces and near micron-sized features. Attention is focused on the coupling between mass transport and fluid flow as well as the effects of surface tension on film profiles over topographical features.

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