On Temperature Transients at Sliding Interface

1969 ◽  
Vol 91 (3) ◽  
pp. 397-405 ◽  
Author(s):  
F. F. Ling
Keyword(s):  
Experimental Investigation ◽  
Theoretical Model ◽  
Stochastic Model ◽  
Sliding Contact ◽  
Interface Temperature ◽  
Temperature Level ◽  
Dynamic Thermocouple ◽  
Thermocouple Method ◽  
Two Temperatures ◽  
Simple Stochastic Model

A simple stochastic model of interface temperature of solids in sliding contact, introduced earlier, has been extended. An experimental investigation has also been carried out, the result of which seems to lend credence to the theoretical model. The model led to the observation that, statistically, there are two temperatures at the interface, both being transients. The first is the average over the geometric contact area at all times, the temperature that is most likely to be measured by dynamic thermocouple method. The second is the time and space average over the instantaneous contacts. It is suggested that, as often as not, it is the latter which should be the reference temperature level upon which activities at the interface depend.

Boiling Heat Transfer With Binary Mixtures: Part I—A Theoretical Model for Pool Boiling

1998 ◽  
Vol 120 (2) ◽  
pp. 380-387 ◽  
Author(s):  
S. G. Kandlikar
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Theoretical Model ◽  
Transfer Coefficient ◽  
Binary Mixtures ◽  
Boiling Heat Transfer ◽  
Present Model ◽  
Pool Boiling ◽  
Interface Temperature ◽  
Pool Boiling Heat Transfer

Experimental evidence available in the literature indicates that the pool boiling heat transfer with binary mixtures is lower than the respective mole- or mass-fraction-averaged value. Although a few investigators have presented analytical work to model this phenomenon, empirical methods and correlations are used extensively. In the present work, a theoretical analysis is presented to estimate the mixture effects on heat transfer. The ideal heat transfer coefficient used currently in the literature to represent the pool boiling heat transfer in the absence of mass diffusion effects is based on empirical considerations, and has no theoretical basis. In the present work, a new pseudo-single component heat transfer coefficient is introduced to account for the mixture property effects more accurately. The liquid composition and the interface temperature at the interface of a growing bubble are predicted analytically and their effect on the heat transfer is estimated. The present model is compared with the theoretical model of Calus and Leonidopoulos (1974), and two empirical models, Calus and Rice (1972) and Fujita et al. (1996). The present model is able to predict the heat transfer coefficients and their trends in azeotrope forming mixtures (benzene/methanol, R-23/R-13 and R-22/R-12) as well as mixtures with widely varying boiling points (water/ethylene glycol and methanol/water).

Cognition, conflict, and doctrine: How groupthink fails on a Clausewitz landscape

2019 ◽  
Vol 17 (2) ◽  
pp. 137-142 ◽  
Author(s):  
Rodrick Wallace
Keyword(s):  
Stochastic Model ◽  
Constrained Optimization ◽  
Real Time ◽  
Institutional Effectiveness ◽  
Shadow Price ◽  
Political Campaigns ◽  
Direct Approach ◽  
Optimization Models ◽  
Anytime Algorithm ◽  
Simple Stochastic Model

Real-time conflict takes place on Clausewitz landscapes most notably marked by fog-of-war and frictional limits, uncertainties, and misperceptions. Imposition of such factors on an opponent is, in fact, a standard tactic of confrontation, from courts of law to commerce, from political campaigns to the battlefield. Time-constrained optimization models of institutional effectiveness, based on ‘anytime algorithm’ methods, suggest that the burden of doctrinal groupthink may become synergistic with fog-of-war and friction to greatly compromise the ability of an institution to respond to shadow price demands imposed by a contending agent or environment. A different, and more direct, approach via a ‘simple’ stochastic model, provides similar insight.

scholarly journals Testing a simple stochastic model for the dynamics of waterfowl aggregations

Oecologia ◽  
2001 ◽  
Vol 128 (4) ◽  
pp. 608-617 ◽  
Author(s):  
Emily D. Silverman ◽  
Mark Kot ◽  
Elizabeth Thompson
Keyword(s):  
Stochastic Model ◽  
Simple Stochastic Model

Influence of Tool Holder Material on Interfacial, Insert and Tool Holder Temperatures During Turning Operation of Gray Iron

2012 ◽  
Author(s):  
Almir K. Kaminise ◽  
Gilmar Guimaraes ◽  
Marcio B. Da Silva
Keyword(s):  
Temperature Distribution ◽  
Carbon Steel ◽  
Cutting Tool ◽  
Gray Iron ◽  
Cutting Fluid ◽  
Interface Temperature ◽  
Turning Operation ◽  
Tool Holder ◽  
Cutting Insert ◽  
Thermocouple Method

Usually studies related to machining temperature consider a system comprised of workpiece, chip and cutting tool, the effect of tool holder material is not taken in account. However, due to its physical properties, the tool holder material, usually carbon steel, has effect in the dissipation of the heat generated. This work studies the effect of the tool holder material on the temperature distribution during the turning operation of gray iron using cemented carbide cutting tool and without cutting fluid. Five tool holders were manufactured from materials with different heat conductivity: carbon steel, stainless steel, titanium, copper and bronze. Temperatures in eight different positions in the tool holder and cutting insert were measured. The average temperature at the chip tool interface was also measured using the tool-work thermocouple method. The results showed that the measured chip tool interface temperature was less affected by the tool holder material, although the temperature distribution at the cutting tool is highly affected.

Simple Stochastic Model for Annual Flows

1990 ◽  
Vol 116 (2) ◽  
pp. 220-232 ◽  
Author(s):  
Andrea G. Capodaglio ◽  
Ugo Moisello
Keyword(s):  
Stochastic Model ◽  
Simple Stochastic Model
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