Steady-State Clearance in Bearings with Thermal Expansion

2000 ◽  
pp. 37-44
Author(s):  
Ralph A. Burton
Keyword(s):  
Thermal Expansion ◽  
Steady State

Non-steady-state measurements of the thermal conductivities of liquid polyphenyls

1963 ◽  
Vol 273 (1353) ◽  
pp. 259-274 ◽  
Keyword(s):  
Thermal Conductivity ◽  
Thermal Expansion ◽  
Steady State ◽  
Temperature Dependence ◽  
Line Source ◽  
Coefficient Of Thermal Expansion ◽  
Liquid Benzene ◽  
Extended Range ◽  
Benzene Toluene ◽  
Effect Of Structure

A line source technique has been developed for non-steady-state measurements of the therm al conductivities of liquids over an extended range of temperature. The accuracy of the method, which is an absolute one, has been critically exam ined. T hermal conductivities of liquid benzene, toluene, diphenyl, o-,m - and^p-terphenyl, estimated to be accurate to + 0*25 % , have been obtained. These results are discussed in terms of the effect of structure on the transport properties of liquids and the relation between the coefficient of thermal expansion and the temperature dependence of thermal conductivity.

scholarly journals Numerical prediction of structural damage due to pressure buildup in subsea oil and gas equipment

2021 ◽  
Vol 11 (6) ◽  
pp. 2691-2707
Author(s):  
Ramechecandane Somassoundirame ◽  
Eswari Nithiyananthan
Keyword(s):  
Boundary Condition ◽  
Thermal Expansion ◽  
Steady State ◽  
Structural Analysis ◽  
Structural Damage ◽  
Oil And Gas ◽  
Numerical Prediction ◽  
Cfd Analysis ◽  
Pressure Buildup ◽  
Pipe Line

AbstractPressure buildup/annular pressure buildup in subsea oil and gas equipment occurs primarily due to the thermal expansion of trapped liquids. With the advent of modern computers, it has become increasingly possible to numerically analyze such problems with commercial codes available in the market. The objective of the present study is to propose a methodology for numerical prediction of structural damage in subsea oil and gas equipment due to pressure buildup. A judicious combination of computational fluid dynamics (CFD) with structural finite element analysis code has been used to perform a sample numerical analysis that is truly representative of a wide class of problems encountered in subsea oil and gas applications. The mitigation of trapped pressure is one among the prime areas of concern in the subsea oil and gas industry. In the present study, CFD analysis is used to determine the maximum pressure buildup due to the thermal expansion of trapped liquids in small leak tight enclosed volumes with rigid walls and the pressure obtained is used as a boundary condition for the structural analysis. In a nutshell, the analysis has been split into three steps (1) a steady-state CFD analysis to determine the temperature distribution within the oil and gas equipment under consideration, (2) the temperature contours obtained from the steady-state analysis are imposed as a boundary condition for the transient analysis to calculate the trapped pressure in the small volumes of interest and finally and (3) a structural analysis is used to determine the damage to the oil and gas equipment. The methodology adapted is similar to a one-way coupled fluid structure interaction analysis, but provides the added advantage of a significant reduction in computational cost. In the present study, the proposed methodology has been extended to a subsea Christmas tree (XT) and the pressure buildup in the hydraulic lines has been calculated. The results obtained using the present technique has been compared with analytical solution. The proposed numerical technique can be applied to any subsea or surface oil and gas equipment where pressure buildup due to trapped volume is a major issue. The findings of this study can help for better understanding of pressure buildup in trapped volumes within subsea/surface oil and gas equipment. This study can be applied to predict the thermal expansion of trapped volumes in subsea XTs, manifolds, pipe line end manifolds (PLEM) and pipe line end termination (PLET) units.

The Redistribution of Load in Bolted Gasketed Joints Subjected to Steady State Thermal Loading

2002 ◽  
Author(s):  
Akli Nechache ◽  
Abdel-Hakim Bouzid
Keyword(s):  
Mechanical Properties ◽  
Thermal Expansion ◽  
Steady State ◽  
Thermal Effects ◽  
Thermal Loading ◽  
Operating Temperature ◽  
Theoretical Models ◽  
Joint Analysis ◽  
Effects Of Temperature

Pressure vessel joints operating at high temperature are often very difficult to seal. The existing flange design methods do not address thermal effects other than the variation of flange material mechanical properties with temperature. It is possible to include the effects of temperature loading in joint analysis, however, presently very few guidelines exist for this type of analysis. This paper outlines the theoretical analysis used for the determination of the steady state operating temperature and the induced loads in flange joints. It details the theoretical equations necessary to predict the temperature and the redistribution of load due to the thermal expansion of the joint components for the case of a pair flange and the case of a flange with a blind-cover. The results from the theoretical models are verified by comparison to finite element results.

Thermal Instability in High-Speed Gearing

1961 ◽  
Vol 83 (1) ◽  
pp. 91-103 ◽  
Author(s):  
W. P. Welch ◽  
J. F. Boron
Keyword(s):  
Thermal Expansion ◽  
Steady State ◽  
Experimental Verification ◽  
Thermal Effects ◽  
High Speed ◽  
Thermal Instability ◽  
Point Of View ◽  
State Point

Thermal-expansion effects in gearing have usually been considered from a steady-state point of view. A theory of thermal instability is developed which takes into account the tendency of the thermal effects to be regenerative. This theory provides an adequate and complete explanation for several previously unexplained cases of tooth failure in high-speed high-horsepower reduction gears. Experimental verification of the theory is presented and some of the conditions for avoiding thermal instability are described.

scholarly journals MONITORING THE DEFORMATION OF HIGH-RISE BUILDINGS IN SHANGHAI LUIJIAZUI ZONE BY TOMO-PSINSAR

2018 ◽  
Vol XLII-3 ◽  
pp. 2535-2539
Author(s):  
L. F. Zhou ◽  
P. F. Ma ◽  
Y. Xia ◽  
C. H. Xie
Keyword(s):  
Thermal Expansion ◽  
Steady State ◽  
Linear Deformation ◽  
Spatiotemporal Filtering ◽  
High Rise ◽  
Persistent Scatterers ◽  
Deformation Velocity ◽  
Thermal Amplitude ◽  
Creep And Shrinkage

In this study, we utilize a Tomography-based Persistent Scatterers Interferometry (Tomo-PSInSAR) approach for monitoring the deformation performances of high-rise buildings, i.e. SWFC and Jin Mao Tower, in Shanghai Lujiazui Zone. For the purpose of this study, we use 31 Stripmap acquisitions from TerraSAR-X missions, spanning from December 2009 to February 2013. Considering thermal expansion, creep and shrinkage are two long-term movements that occur in high-rise buildings with concrete structures, we use an extended 4-D SAR phase model, and three parameters (height, deformation velocity, and thermal amplitude) are estimated simultaneously. Moreover, we apply a two-tier network strategy to detect single and double PSs with no need for preliminary removal of the atmospheric phase screen (APS) in the study area, avoiding possible error caused by the uncertainty in spatiotemporal filtering. Thermal expansion is illustrated in the thermal amplitude map, and deformation due to creep and shrinkage is revealed in the linear deformation velocity map. The thermal amplitude map demonstrates that the derived thermal amplitude of the two high-rise buildings both dilate and contract periodically, which is highly related to the building height due to the upward accumulative effect of thermal expansion. The linear deformation velocity map reveals that SWFC is subject to deformation during the new built period due to creep and shrinkage, which is height-dependent movements in the linear velocity map. It is worth mention that creep and shrinkage induces movements that increase with the increasing height in the downward direction. In addition, the deformation rates caused by creep and shrinkage are largest at the beginning and gradually decrease, and at last achieve a steady state as time goes infinity. On the contrary, the linear deformation velocity map shows that Jin Mao Tower is almost stable, and the reason is that it is an old built building, which is not influenced by creep and shrinkage as the load is relaxed and dehydration proceeds. This study underlines the potential of the Tomo-PSInSAR solution for the monitoring deformation performance of high-rise buildings, which offers a quantitative indicator to local authorities and planners for assessing potential damages.

The Application of Steady-State Thermal Expansion of the Rolls in Thickness Setup Model for HSM

2014 ◽  
Vol 941-944 ◽  
pp. 1696-1699
Author(s):  
Geng Sheng Ma ◽  
Fang Chen Yin ◽  
Xiao Yan Zhu ◽  
Wen Peng ◽  
Jian Zhao Cao ◽  
...  
Keyword(s):  
Thermal Expansion ◽  
Temperature Field ◽  
Steady State ◽  
Rolling Process ◽  
Strip Thickness ◽  
Rolled Strip ◽  
Adaptive Model ◽  
Finite Element Software ◽  
Long Time ◽  
Hot Rolled

The hot rolled strip thickness accuracy sometimes can not be guaranteed after a long time for waiting for slabs or other reasons. The reason is when rolling, the rollgap adaptive model has considered the thermal expansion of the roll. So when rolling is restarted, thermal expansion of the rolls must be cleared in order to accurately calculate the setup rollgap value. The finite element software ANSYS is used to calculate the temperature field and thermal expansion amount of the rolls in the rolling process. Application results show that this method can improve the accuracy of strip thickness.

On the generalized Forchheimer—Stokes—Fourier systems under the Beavers—Joseph—Saffman boundary condition

2013 ◽  
Vol 143 (1) ◽  
pp. 101-120
Author(s):  
Luisa Consiglieri
Keyword(s):  
Thermal Conductivity ◽  
Boundary Condition ◽  
Porous Medium ◽  
Thermal Expansion ◽  
Steady State ◽  
Boundary Value Problem ◽  
Temperature Dependence ◽  
Time Dependent ◽  
Physical Parameters ◽  
Nonlinear Character

A Stokesian fluid in motion along a porous medium saturated by the same fluid is modelled by the Beavers—Joseph—Saffman boundary-value problem to generalized Forchheimer—Stokes—Fourier systems: what we call the Beavers—Joseph—Saffman (BJS) problem. The model has nonlinear character given by the temperature dependence of physical parameters such as the viscosity, the permeability, the thermal conductivity and the thermal expansion. The paper is concerned with the study of the steady-state and the time-dependent regimes via the Galerkin and the Faedo—Galerkin techniques, respectively.

Two-Wavelength Thermoreflectance and its Application in Temperature Measurement of Micro-Electronic Devices

2018 ◽  
Author(s):  
Hongjie Zhang ◽  
Sy-Bor Wen
Keyword(s):  
Thermal Expansion ◽  
Steady State ◽  
Temperature Measurement ◽  
Imaging Technique ◽  
Electronic Devices ◽  
Target Movement ◽  
Steady State Operation ◽  
Steady State Temperature ◽  
Higher Temperature ◽  
Low Sensitivity

A two-wavelength thermoreflectance (2WTR) imaging technique is developed to conduct steady-state temperature measurement of miniature electronic devices, such as micro-scale gold resistors. Compared with traditional single wavelength thermoreflectance (TR) imaging requiring comparison of TR signals from a target under heated and unheated conditions, 2WTR method obtains temperature information from heated target under operation directly. Therefore, 2WTR is not affected by movement of a heated target due to thermal expansion. Note that thermal expansion of targets between heated and unheated conditions is a main constraint of current TR imaging of miniature targets. In addition to the low sensitivity to the target movement, the new 2WTR can provide even higher temperature resolution than single wavelength TR by appropriately selecting the adopted two wavelength to have different signs of TR coefficients. With this new TR imaging technique, we successfully measure temperature distribution of a microscale gold resistor under steady-state operation, which are challenging to be obtained by traditional single wavelength TR method.

The Effect of Steady State Thermal Loading on the Deflections of a Flanged Joint With a Cover Plate

2002 ◽  
Author(s):  
Abdel-Hakim Bouzid ◽  
Akli Nechache ◽  
Warren Brown
Keyword(s):  
Thermal Expansion ◽  
Steady State ◽  
Temperature Profile ◽  
Thermal Effects ◽  
Thermal Loading ◽  
Cover Plate ◽  
Asme Code ◽  
Effects Of Temperature ◽  
Bolted Flange

It is well recognized that bolted flange joints operating at high temperature are often very difficult to seal. The existing flange design methods including that of the ASME code do not address thermal effects other than the variation of flange and bolt material mechanical properties with temperature. It is possible to include the effects of temperature loading in the flexibility analysis of the joint. However, the temperature profile to be known to determine the radial and axial thermal expansion displacements of the joint elements to be used in the analysis. This paper outlines the theoretical analysis used for the determination of the steady state operating temperature profile, the thermal expansion displacements of the joint components and the bolt load changes for the case of a flange joint with a blind cover. The results from the proposed analytical model are verified by comparison to finite element results of three different sizes of bolted joints.

Calculation of Axial Thermal Expansion for a 1000MW Nuclear Steam Turbine HIP Casing

2017 ◽  
Author(s):  
Ziyue Mei ◽  
Hengliang Zhang ◽  
Danmei Xie ◽  
Yanan Guo ◽  
Xiuqun Hou ◽  
...  
Keyword(s):  
Thermal Expansion ◽  
Steady State ◽  
Steam Turbine ◽  
Load Shedding ◽  
Transfer Coefficients ◽  
Safe Operation ◽  
Element Analysis ◽  
Steady State Condition ◽  
Heat Transfer Coefficients ◽  
Turbine Casing

Steam turbine casing axial thermal expansion is of great significance to the safe operation for nuclear units. Taking a certain 1000MW nuclear steam turbine’s HIP casing as an object, this paper calculates the HIP casing absolute axial thermal expansions under such conditions as: steady-state, startup and load shedding. Firstly, a 3D model of the nuclear steam turbine HIP casing is this established by using Pro/E software. Secondly, the heat transfer coefficients of every surface of HIP casing are calculated. Finally, the HIP casing temperature field and the absolute axial thermal expansions under three conditions are calculated and analyzed by using finite element analysis software. The result shows that, the HIP casing axial thermal expansions are 22.642mm and 22.529mm under steady-state condition and startup condition respectively. While, under load shedding condition, minimum axial expansion is 16.202mm and it increases to 22.491mm at rated load.

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