MSimon wrote:nferguso wrote:The perspective of discussion I have seen is in reference to minimizing the first wall surface area. But how about taking the opposite tack? Embrace the hot, I say! Make the magnet housings as big as the fluxes can allow. Surface area goes up with the square, but coolant volume goes up with the cube. You have more room for mechanical rigidity. Bigger might mean more congenial magnet constraints.
Go with steam turbines as your major energy output. Worry about the mega-voltage later. KISA. If break-even is reached, platoons of engineers will optimize the design for applications.
Heat transfer is an area problem. It doesn't matter how much water you pump through a pipe. What matters is how much contacts the surface. Turbulent flow is the thing. High surface to volume ratios help keep the Reynolds number up.
You probably already thought of this, but it might be of interest to others. Does everyone remeber those old pith ball experiments where a pith ball is suspended between two charged plates ? The pith ball bounces back and forth rapidly between the plates exchanging charges.
Well, from what i've been reading over the past couple of years, this concept also works for air, and at least one researcher was experimenting with an ion cooling system for microprocessors. Because of a high voltage charge on the plates, the air molecules are brought into intimate contact with the suface, and therefore the heat transfer per molecule is maxed out. With air flowing over the surface in a conventional cooling system, air forms a boundary layer next to the surface that prevents efficient heat transfer.
The Ion air cooling system punches through the boundary layer and maximizes air contact with the surface. From what I remeber, the energy required to cool something using this technique is dramatically lower than using a cooling fan.
What am I getting at? If this system works for air, it seems to me the same concept should work for a non conductive liquid.
Furthermore, if 20% of your alphas are striking the MagGrid, all that is required to achieve a potential difference between the outside wall of the grid and the surface of the next layer is to control the bleedoff of voltage from the outside of the MagGrid. Maintain the Inner layer at a lower potential, and the coolant molecules should ping back and forth between inner and outer layer as it flows through the system.
Talk about your turbulence ! I don't think you can get more turbulent than that !
Just an observation. Might be wrong. Dunno.
David