Differential thermal expansion of pore fluids: Fracture propagation and microearthquake production in hot pluton environments

1977 ◽  
Vol 82 (17) ◽  
pp. 2515-2522 ◽  
Author(s):  
Richard B. Knapp ◽  
Jerry E. Knight
Keyword(s):  
Thermal Expansion ◽  
Fracture Propagation ◽  
Pore Fluids ◽  
Differential Thermal Expansion

Thermally Induced Synchronous Instability of a Radial Inflow Overhung Turbine: Part I

1997 ◽  
Author(s):  
H. B. Faulkner ◽  
W. F. Strong ◽  
R. G. Kirk
Keyword(s):  
Thermal Expansion ◽  
Operating Speed ◽  
Lateral Motion ◽  
Turbine Wheel ◽  
Thermally Induced ◽  
Lateral Dynamics ◽  
Morton Effect ◽  
Speed Range ◽  
Differential Thermal Expansion ◽  
Rotor Dynamic

Abstract This paper is in two parts, and concerns the lateral dynamics of a large turbocharger rotor with overhung wheels. Initial rotor dynamic analysis indicated no excessive motion in the operating speed range. However, testing showed excessive motion, which was initially traced to the radial-inflow turbine wheel becoming loose on the shaft, due to transient differential thermal expansion in the wheel on startup. The attachment of the wheel was modified to eliminate this problem. The discussion up to this point is in Part I of the paper, and the remainder is in Part II. The wheel attachment modification extended the range of satisfactory operation upward considerably, but excessive lateral motion was again encountered near the upper end of the operating speed range. This behavior was traced to thermal bowing of the shaft at the turbine end, known as the Morton Effect. The turbine end bearing was modified to eliminate this problem, and satisfactory operation was then achieved throughout the operating speed range.

Optimization of a Ceramic Circuit Board Clamp

2012 ◽  
Vol 2012 (HITEC) ◽  
pp. 000394-000401
Author(s):  
David A. Glowka ◽  
Randy A. Normann
Keyword(s):  
Thermal Expansion ◽  
Fixed Point ◽  
Elevated Temperature ◽  
Design Optimization ◽  
Parametric Study ◽  
Material Selection ◽  
Circuit Board ◽  
Differential Thermal Expansion ◽  
Logging Tool ◽  
Clamping Pressure

This paper documents the design optimization of a board-mounting system for securing a ceramic or other heavy circuit board to the electronics chassis in a wireline logging tool. A clamp fixes the extreme lower end of the circuit board to the chassis while allowing the board and chassis to undergo differential thermal expansion above that fixed point, through the use of sliding board mounts. After developing equations that describe the stress, deflection, and thermal expansion of the clamp/board assembly, they are used to select the geometry and material options available in the design. Results of a parametric study are presented that demonstrate how material selection determines whether the clamping pressure on the circuit board improves or degrades at elevated temperature, and how the geometries of the clamp components affect the magnitudes of the forces, deflections, and setting torque of the clamp.

Heat-Exchanger Tube-Sheet Design—2: Fixed Tube Sheets

1952 ◽  
Vol 19 (2) ◽  
pp. 159-166
Author(s):  
K. A. Gardner
Keyword(s):  
Thermal Expansion ◽  
Heat Exchanger ◽  
Tube Sheet ◽  
Heat Exchanger Tube ◽  
Shell Side ◽  
Side Pressure ◽  
Differential Thermal Expansion ◽  
Design Factors ◽  
Exchanger Tube ◽  
Design Pressure

Abstract It is shown that “fixed” tube sheets may be designed in exactly the same manner as “floating” tube sheets with the same boundary restraint, provided that a fictitious uniform “equivalent design pressure” is used in the calculations instead of the actual hydrostatic pressure. This equivalent pressure is evaluated in terms of tube-side pressure, shell-side pressure, differential thermal expansion, and the condition of boundary restraint. The design factors for all tube sheets presented in an earlier paper are shown to be well represented by very simple expressions when the fundamental design parameter xa becomes large.

Estimations Of Changes in Microcrack-Population, Elastic Modulus, and Permeability, Due to Differential-Thermal Expansion in Plutonic Rock Surrounding A Nuclear Fuel Waste Disposal Vault

1985 ◽  
Vol 50 ◽  
Author(s):  
B. J. Wilkins ◽  
Y. Liner ◽  
G. L. Rigby
Keyword(s):  
Thermal Expansion ◽  
Elastic Modulus ◽  
Nuclear Fuel ◽  
Plutonic Rock ◽  
Time Dependent ◽  
Far Field ◽  
Rate Of Escape ◽  
Differential Thermal Expansion ◽  
Nuclear Fuel Waste ◽  
Canada Limited

AbstractAtomic Energy of Canada Limited is studying the disposal of nuclear fuel-waste in a vault in plutonic rock. An important part of this study is to develop models to assess the rate of escape of waste components to the biosphere. In these models time-dependent changes in the system are important. One such change is the increase in temperature of the rock mass immediately surrounding the vault, and in the far-field. Differential- thermal expansion between rock constituents (crystals), and the expansion of trapped water, will produce microcracking and, hence, possibly changes in intact-rock elastic modulus and permeability. This paper describes the model devised to estimate the extent of microcracking in rock surrounding a vault, and the anticipated changes in rock elastic modulus and permeability. The model is applied to a possible vault, located at various depths in plutonic rock typical of the Canadian Shield. It estimates the dimensions of an envelope outside of which the influence of the vault on microcracking will be negligible.

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