Calorimetric bridge schemes for thermophysical measurements under steady-state thermal conditions

1995 ◽  
Vol 38 (9) ◽  
pp. 1017-1023
Author(s):  
T. G. Grishchenko ◽  
L. V. Dekusha
Keyword(s):  
Steady State ◽  
Thermal Conditions

scholarly journals An experimental study of the influence of a moving person on airflow characteristics and thermal conditions with diffuse ceiling ventilation

2020 ◽  
Vol 29 (6) ◽  
pp. 860-880 ◽  
Author(s):  
Weixin Zhao ◽  
Sami Lestinen ◽  
Simo Kilpeläinen ◽  
Risto Kosonen
Keyword(s):  
Steady State ◽  
Temperature Gradient ◽  
Experimental Studies ◽  
Thermal Conditions ◽  
Human Movement ◽  
State Condition ◽  
Vertical Temperature ◽  
Steady State Condition ◽  
Power Spectral ◽  
Local Thermal Comfort

The influence of occupants'’ movements should be considered when analysing local thermal comfort. This study presents the effect of human movement on airflow characteristics and local thermal conditions with diffuse ceiling ventilation by experimental studies. A simulated person moving was used to study the human movement in an office. In these experiments, three moving speeds were studied: 0.3, 0.6 and 1.0 m/s. The simulated person moved in four cycle patterns: continuous moving and with 5 s, 10 s and 15 s interval breaks between each turn. Three heat gain levels of 40, 60 and 80 W/m2 were evaluated in the chamber. The results indicate that the human movement decreased vertical temperature gradient compared with the steady-state condition. Instead, the moving intervals would have no effect on the vertical air temperature gradient. The power spectral density was increased by 90% due to the person movement compared with the steady-state condition. The moving person would create different micro-environments close to work stations than close to the moving area.

scholarly journals Transient Thermal Response of Turbulent Compressible Boundary Layers

2011 ◽  
Vol 133 (8) ◽  
Author(s):  
Hongwei Li ◽  
M. Razi Nalim ◽  
Charles L. Merkle
Keyword(s):  
Boundary Layer ◽  
Steady State ◽  
Laminar Flow ◽  
Thermal Boundary Layer ◽  
Thermal Response ◽  
Thermal Conditions ◽  
Steady State Solution ◽  
Similarity Transformations ◽  
Keller Box Method ◽  
Transient Thermal

A numerical method is developed with the capability to predict transient thermal boundary layer response under various flow and thermal conditions. The transient thermal boundary layer variation due to a moving compressible turbulent fluid of varying temperature was numerically studied on a two-dimensional semi-infinite flat plate. The compressible Reynolds-averaged boundary layer equations are transformed into incompressible form through the Dorodnitsyn–Howarth transformation and then solved with similarity transformations. Turbulence is modeled using a two-layer eddy viscosity model developed by Cebeci and Smith, and the turbulent Prandtl number formulation originally developed by Kays and Crawford. The governing differential equations are discretized with the Keller-box method. The numerical accuracy is validated through grid-independence studies and comparison with the steady state solution. In turbulent flow as in laminar, the transient heat transfer rates are very different from that obtained from quasi-steady analysis. It is found that the time scale for response of the turbulent boundary layer to far-field temperature changes is 40% less than for laminar flow, and the turbulent local Nusselt number is approximately 4 times that of laminar flow at the final steady state.

Theory analysis of the steady-state surface temperature on rolling tire

2011 ◽  
Vol 226 (5) ◽  
pp. 1278-1289 ◽  
Author(s):  
Y Li ◽  
S Zuo ◽  
X Duan ◽  
X Guo ◽  
C Jiang
Keyword(s):  
Steady State ◽  
Surface Temperature ◽  
Heat Generation ◽  
Heat Dissipation ◽  
Field Tests ◽  
Thermal Conditions ◽  
Theory Model ◽  
Theory Analysis ◽  
Tire Pressure ◽  
Generation Capacity

The mechanisms of heat generation and heat dissipation of tire are first discussed, and the heat generation capacity and the heat dissipation capacity per unit time are obtained through the analysis of both tire contact pressure distribution and heat dissipation method. Then,according to heat balance condition of tire, the theory model of the steady-state surface temperature of tire is established based on tire temperature field tests. Finally, the effects of speed, load, and tire pressure on the steady-state surface temperature of tire are analysed. The results show that the established model of the steady-state surface temperature of rolling tire is feasible, and the results can reflect the thermal conditions of tire, and therefore provides a theoretical foundation to predict the steady-state surface temperature for various types of tires under different driving conditions.

Studies on Water in the Hydration Chamber of a Modified Electron Microscope

1970 ◽  
Vol 28 ◽  
pp. 544-545
Author(s):  
R. C. Moretz ◽  
G. G. Hausner ◽  
D. F. Parsons
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Electron Microscope ◽  
Steady State ◽  
Room Temperature ◽  
Small Mass ◽  
Equilibrium Pressure ◽  
Biological Objects ◽  
Mechanical Pump ◽  
Differential Pumping

Use of the electron microscope to examine wet objects is possible due to the small mass thickness of the equilibrium pressure of water vapor at room temperature. Previous attempts to examine hydrated biological objects and water itself used a chamber consisting of two small apertures sealed by two thin films. Extensive work in our laboratory showed that such films have an 80% failure rate when wet. Using the principle of differential pumping of the microscope column, we can use open apertures in place of thin film windows.Fig. 1 shows the modified Siemens la specimen chamber with the connections to the water supply and the auxiliary pumping station. A mechanical pump is connected to the vapor supply via a 100μ aperture to maintain steady-state conditions.

Continuous hydrogenolysis of acetal-stabilized lignin in flow

2021 ◽  
Author(s):  
Wu Lan ◽  
Yuan Peng Du ◽  
Songlan Sun ◽  
Jean Behaghel de Bueren ◽  
Florent Héroguel ◽  
...  
Keyword(s):  
Steady State ◽  
Challenges And Opportunities

We performed a steady state high-yielding depolymerization of soluble acetal-stabilized lignin in flow, which offered a window into challenges and opportunities that will be faced when continuously processing this feedstock.

Network reconstruction based on steady-state data

2008 ◽  
Vol 45 ◽  
pp. 161-176 ◽  
Author(s):  
Eduardo D. Sontag
Keyword(s):  
Steady State ◽  
Reverse Engineering ◽  
Theoretical Method ◽  
Network Reconstruction ◽  
Quasi Steady State ◽  
State Data

This paper discusses a theoretical method for the “reverse engineering” of networks based solely on steady-state (and quasi-steady-state) data.

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