Centrifugal and Thermal Stresses in Rotating Disks

1948 ◽  
Vol 15 (4) ◽  
pp. 322-326
Author(s):  
W. R. Leopold
Keyword(s):  
Temperature Gradient ◽  
Thermal Stresses ◽  
Elevated Temperatures ◽  
Rotating Disk ◽  
Heat Transfer Analysis ◽  
Rotating Disks ◽  
Radial Temperature Gradient ◽  
Radial Temperature ◽  
Disk Material ◽  
Method Of Solution

Abstract A general semigraphical method, a combination and continuation of the solutions indicated by Stodola and Timoshenko, was found by which the thermal and centrifugal stresses in a rotating disk of any arbitrary profile could be determined. This relatively simple and rapid method of solution requires for its application elementary arithmetic involved in the completion of a tabular form sheet, a temperature gradient along the radius of the disk, which may be approximated by an exponential function of the radius, and easily accommodates changes in the physical properties of the disk material at elevated temperatures. A disk profile and expected radial temperature gradient, as determined from heat-transfer analysis, were taken as an example, and the complete disk stresses calculated directly to demonstrate the use of the method.

Optimum Design of Inhomogeneous Rotating Disks for Minimum Creep Induced Radial Displacement

2011 ◽  
Vol 133 (5) ◽  
Author(s):  
Behrooz Farshi ◽  
Jalal Bidabadi
Keyword(s):  
Temperature Gradient ◽  
Thermal Stresses ◽  
Elevated Temperatures ◽  
Thickness Distribution ◽  
Turbine Blades ◽  
Rotating Disk ◽  
Optimization Method ◽  
Rotating Disks ◽  
Power Generators ◽  
Disk Material

Gas turbine disks are subject to mechanical stresses due to centrifugal forces exerted by the blades, as well as thermal stresses due to high temperature gradient. High stresses in the presence of elevated temperatures cause the rotating disk material to undergo considerable creep. This phenomenon is significant particularly in cases of turbine blades for power generators, which run almost continuously. Creep strains, in time, lead to deformations resulting in increase of the disk diameter, causing the clearance between blade tips and the turbine’s outer shell to reduce in time. As the above clearance gap is usually limited, this matter is of concern in the design of such equipment for long life. In this investigation, an optimization method is formulated, which is capable of proportioning the thickness distribution of inhomogeneous rotating disks under temperature gradient, so that their long term radii increase due to creep would be minimum. An example is given, which shows the viability of the method.

Analysis of High-Speed Rotating Disks With Variable Thickness and Inhomogeneity

1994 ◽  
Vol 61 (1) ◽  
pp. 186-191 ◽  
Author(s):  
Kai-Yuan Yeh ◽  
R. P. S. Han
Keyword(s):  
High Speed ◽  
Elevated Temperatures ◽  
Rotating Disk ◽  
Rotating Disks ◽  
Analytic Expressions ◽  
Inhomogeneous Temperature ◽  
Inhomogeneous Temperature Field ◽  
Thermoelastic Stresses ◽  
Shrink Fit ◽  
Annular Disks

A rotating disk with varying thickness and inhomogeneity, and subjected to a steady, inhomogeneous temperature field is analyzed. To handle the arbitrary profile, the disk is discretized into a series of uniform annular disks possessing constant material properties and then solved by the step-reduction method. Analytic expressions for thermoelastic stresses are given, and based on these results, the formulation is extended to include the calculation of shrink fit, the solving of the inverse problem for equistrength rotating disks, and the computations of plastic stresses and creep at elevated temperatures.

The Effect of Modified Crucible Design and Seed Attachment on SiC Crystal Grown by PVT

2013 ◽  
Vol 740-742 ◽  
pp. 77-80
Author(s):  
Jung Young Jung ◽  
Sang Il Lee ◽  
Mi Seon Park ◽  
Doe Hyung Lee ◽  
Hee Tae Lee ◽  
...  
Keyword(s):  
Crystal Growth ◽  
Temperature Gradient ◽  
Single Crystals ◽  
Crystal Quality ◽  
Full Width ◽  
Half Maximum ◽  
Radial Temperature Gradient ◽  
Radial Temperature ◽  
Better Than

The present research was focused to investigate the effect of internal crucible design that influenced the 4H-SiC crystal growth onto a 6H-SiC seed by PVT method. The crucible design was modified to produce a uniform radial temperature gradient in the growth cell. The seed attachment was also modified with a use of polycrystalline SiC plate. The crystal quality of 4H-SiC single crystals grown in modified crucible and grown with modified seed attachment was revealed to be better than that of crystal grown in conventional crucible. The full width at half maximum (FWHM) values of grown SiC crystals in the conventional crucible, the modified seed attachment and the modified crucible were 285 arcsec, 134 arcsec and 128 arcsec, respectively. The micropipe density (MPD) of grown SiC crystals in the conventional crucible, the modified seed attachment and the modified crucible were 101ea/cm^2, 81ea/cm^2 and 42ea/cm^2, respectively.

Study on the transient temperature distribution of new conical friction plate under sliding friction

2021 ◽  
pp. 095440702110696
Author(s):  
Yanzhong Wang ◽  
Peng Liu
Keyword(s):  
Temperature Distribution ◽  
Temperature Gradient ◽  
Temperature Rise ◽  
Friction Surface ◽  
Sliding Friction ◽  
Conical Surface ◽  
Transient Temperature ◽  
Radial Temperature Gradient ◽  
Radial Temperature ◽  
Friction Plate

Conical friction surface is a novel configuration for friction plate in transmission. Numerical FEA models for transient heat transfer and distribution of conically grooved friction plate have been established to investigate the thermal behavior of the conical surface with different configurations. The finite element method is used to obtain the numerical solution, the temperature test data of conical surface are obtained by the friction test rig. In order to study and compare the temperature behavior of conically grooved friction plate, several three-dimensional transient temperature models are established. The heat generated on the friction interface during the continuous sliding process is calculated. Two different pressure conditions were defined to evaluate the influence of different load conditions on temperature rise and the effects of conical configuration parameters on surface temperature distribution are investigated. The results show that the radial temperature gradient on conical friction surface is obvious. The uniform pressure condition could be used when evaluating the temperature rise of conically grooved friction plate. The increase of the cone height could improve the radial temperature gradient of the conically grooved friction plate.

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