scholarly journals Comparison of gyrokinetic stability code calculated critical ion temperature gradients and growth rates to DIII-D measured gradients and diffusivities

2003 ◽  
Vol 10 (11) ◽  
pp. 4419-4426 ◽  
Author(s):  
D. R. Baker ◽  
G. M. Staebler ◽  
C. C. Petty ◽  
C. M. Greenfield ◽  
T. C. Luce
Keyword(s):  
Growth Rates ◽  
Temperature Gradients ◽  
Ion Temperature

Effects of ion temperature gradients on the formation of drift-Alfvén vortex structures in dusty plasmas

2002 ◽  
Vol 9 (5) ◽  
pp. 1539-1543 ◽  
Author(s):  
O. G. Onishchenko ◽  
O. A. Pokhotelov ◽  
R. Z. Sagdeev ◽  
V. P. Pavlenko ◽  
L. Stenflo ◽  
...  
Keyword(s):  
Dusty Plasmas ◽  
Vortex Structures ◽  
Temperature Gradients ◽  
Ion Temperature

Simulation of Nucleate Boiling With Interfacial Temperature Gradients and Sharp Interface

2018 ◽  
Author(s):  
Isaac Perez-Raya ◽  
Satish G. Kandlikar
Keyword(s):  
Heat Transfer ◽  
Contact Line ◽  
Growth Rates ◽  
Bubble Growth ◽  
Heated Surface ◽  
Nucleate Boiling ◽  
Bubble Nucleation ◽  
Heat Fluxes ◽  
Temperature Gradients ◽  
Interfacial Temperature

Effective heat transfer techniques benefit the development of nuclear and fossil fuel powered steam generators, high power electronic devices, and industrial refrigeration systems. Boiling dissipates large heat fluxes while keeping a low and a constant surface temperature. However, studies of the fluid behavior surrounding the bubble and the heat transfer near the contact-line are scare due to difficulties of flow visualization, chaotic conditions, and small length scales. The preset study shows the simulation of bubble growth over a heated surface from conception to departure. The computation of mass transfer with interfacial temperature gradients leads to proper bubble growth rates. Models to include the interface sharpness uncover the dynamic and thermal interaction between the interface and the fluid. Results indicate that the nucleation of a bubble (in water at 1 atm with 6.2 K wall superheat) has an influence region of 2Db (where Db is the departure bubble diameter). In addition, results reveal a thin thermal film near the interface that increases the heat transfer at the contact-line region. Numerical bubble growth rates compare well with experimental data on single bubble nucleation.

Tripolar vortex formation in dense quantum plasma with ion-temperature-gradients

2012 ◽  
Vol 19 (5) ◽  
pp. 052303 ◽  
Author(s):  
Anisa Qamar ◽  
Ata-ur-Rahman ◽  
Arshad M. Mirza
Keyword(s):  
Vortex Formation ◽  
Temperature Gradients ◽  
Quantum Plasma ◽  
Ion Temperature

scholarly journals A comparison of turbulent transport in a quasi-helical and a quasi-axisymmetric stellarator

2019 ◽  
Vol 85 (5) ◽  
Author(s):  
I. J. McKinney ◽  
M. J. Pueschel ◽  
B. J. Faber ◽  
C. C. Hegna ◽  
J. N. Talmadge ◽  
...  
Keyword(s):  
Heat Flux ◽  
Growth Rates ◽  
Linear Growth ◽  
Turbulent Transport ◽  
Heat Fluxes ◽  
Ion Temperature ◽  
Ion Temperature Gradient ◽  
Spatially Extended ◽  
Normalized Units ◽  
The Relationship

Ion-temperature-gradient-driven (ITG) turbulence is compared for two quasi-symmetric (QS) stellarator configurations to determine the relationship between linear growth rates and nonlinear heat fluxes. We focus on the quasi-helically symmetric (QHS) stellarator HSX and the quasi-axisymmetric (QAS) stellarator NCSX. In normalized units, HSX exhibits higher growth rates than NCSX, while heat fluxes in gyro-Bohm units are lower in HSX. These results hold for simulations made with both adiabatic and kinetic electrons. The results show that HSX has a larger number of subdominant modes than NCSX and that eigenmodes are more spatially extended in HSX. We conclude that the consideration of nonlinear physics is necessary to accurately assess the heat flux due to ITG turbulence when comparing QS stellarator equilibria.

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