Confinement of a fusion plasma by a cold gas blanket

1977 ◽  
Vol 55 (12) ◽  
pp. 1047-1054 ◽  
Author(s):  
Boye Ahlborn
Keyword(s):  
Shock Wave ◽  
Power Density ◽  
Fusion Reactor ◽  
Magnetic Fusion ◽  
Auxiliary Heating ◽  
Fusion Plasma ◽  
Thermal Front ◽  
Ablation Front ◽  
Cold Gas

The particle end losses from a linear magnetic fusion reactor can be suppressed by establishing an ablation front in a cold gas blanket. The power density W(W/cm2) to drive the thermal front may be drawn from inside (energy end losses) or outside (auxiliary heating). With W below 109 W/cm2 and a D–T blanket the particle outflow is retarded. With higher W values the flow is completely stopped and the fusion plasma is recompressed by a shock wave traveling inwards from the ends.

Comparison of Preanode and Postanode Carbon Dioxide Separation for IGFC Systems

2010 ◽  
Vol 132 (6) ◽  
Author(s):  
Eric Liese
Keyword(s):  
Fuel Cell ◽  
Power Density ◽  
Co2 Capture ◽  
Coal Gasification ◽  
Combined Cycle ◽  
Energy Technology ◽  
Integrated Gasification Combined Cycle ◽  
Lower Efficiency ◽  
Integrated Gasification ◽  
Cold Gas

This paper examines the arrangement of a solid oxide fuel cell (SOFC) within a coal gasification cycle, this combination generally being called an integrated gasification fuel cell cycle. This work relies on a previous study performed by the National Energy Technology Laboratory (NETL) that details thermodynamic simulations of integrated gasification combined cycle (IGCC) systems and considers various gasifier types and includes cases for 90% CO2 capture (2007, “Cost and Performance Baseline for Fossil Energy Plants, Vol. 1: Bituminous Coal and Natural Gas to Electricity,” National Energy Technology Laboratory Report No. DOE/NETL-2007/1281). All systems in this study assume a Conoco Philips gasifier and cold-gas clean up conditions for the coal gasification system (Cases 3 and 4 in the NETL IGCC report). Four system arrangements, cases, are examined. Cases 1 and 2 remove the CO2 after the SOFC anode. Case 3 assumes steam addition, a water-gas-shift (WGS) catalyst, and a Selexol process to remove the CO2 in the gas cleanup section, sending a hydrogen-rich gas to the fuel cell anode. Case 4 assumes Selexol in the cold-gas cleanup section as in Case 3; however, there is no steam addition, and the WGS takes places in the SOFC and after the anode. Results demonstrate significant efficiency advantages compared with IGCC with CO2 capture. The hydrogen-rich case (Case 3) has better net electric efficiency compared with typical postanode CO2 capture cases (Cases 1 and 2), with a simpler arrangement but at a lower SOFC power density, or a lower efficiency at the same power density. Case 4 gives an efficiency similar to Case 3 but also at a lower SOFC power density. Carbon deposition concerns are also discussed.

scholarly journals Shock Initiation of a Satellite Tank under Debris Hypervelocity Impact

2019 ◽  
Vol 9 (19) ◽  
pp. 3957
Author(s):  
Zhao ◽  
Zhao ◽  
Cui ◽  
Wang
Keyword(s):  
Shock Wave ◽  
Power Density ◽  
Wave Theory ◽  
Hypervelocity Impact ◽  
Shock Initiation ◽  
One Dimensional ◽  
Minimum Power ◽  
Shock Wave Pressure ◽  
The One ◽  
Debris Impact

For the risk assessment of a satellite to determine whether the satellite tank explodes under the hypervelocity impact, the Walker–Wasley criterion is selected to predict the shock initiation of the satellite tank. Then, the minimum power density of liquid hydrazine is determined based on the tests, the expressions of shock wave pressure and pressure duration are constructed based on the one-dimensional wave theory, and the initiation criterion for the liquid hydrazine tank is established. Finally, numerical simulation and the initiation criterion are adopted to calculate the power density in the satellite tank under the debris impact at the velocity of 10 km/s. The calculated power density agrees well with the simulated power density, they are both larger than the minimum power density, demonstrating that the shock wave generated by the hypervelocity impact is sufficient to trigger an explosion in the satellite tank.

Optimization of Cold Gas Dynamic Spray Processes by Computational Simulation

2007 ◽  
Author(s):  
Hidemasa Takana ◽  
Kazuhiro Ogawa ◽  
Tetsuo Shoji ◽  
Hideya Nishiyama
Keyword(s):  
Shock Wave ◽  
Electrostatic Force ◽  
Particle Diameter ◽  
Integrated Model ◽  
Viscous Drag ◽  
Spray Process ◽  
Gas Dynamic ◽  
Cold Gas Dynamic Spray ◽  
Gas Dynamic Spray ◽  
Cold Gas

An integrated model of compressible thermofluid, splat formation and coating formation for a cold dynamic spray process has been established. In-flight behavior of nano-micro particles and the interaction between the shock wave and the particles in a supersonic jet flow impinging onto the substrate and further particle acceleration with electrostatic force are clarified in detail by considering viscous drag force, flow acceleration, added mass, gravity, Basset history force, Saffman lift force, Brownian motion, thermophoresis and electrostatic force. The effect of electrostatic acceleration becomes more significant with the decrease in particle diameter even in the presence of unavoidable shock wave. As a result, electrostatic acceleration can broaden the application range of operating particle diameter in a cold gas dynamic spray process to form a robust and activated coating. Finally, based on the integrated model, the coating thickness characteristics in an electrostatic assisted cold dynamic spray process are evaluated.

Sign in / Sign up

Export Citation Format

Share Document