Quote:
Originally posted by myv65
Ah no. Not sure where you get your info, but for internal flows, the crossover occurs at a Reynold's number of about 2300. Re = rho * V * D / mu. With rho = 1000 kg/m^2, V ~ 1 m/s, D = 0.05 m, and mu = 0.001 N-s/m^2, Re ~ 50,000 which is well into the turbulent region. Laminar internal flows require extremely low velocity.
Maybe, but probably not. This one is very counter-intuitive, but the flow would probably be highest at the tube farthest from the entrance/exit. I work with manifolds much like this and test many in a lab. In this arrangement, flow would darn near stagnate in the first couple of cross tubes.
As to BigBen2k's original question, it comes down to velocity and surface area. Them's that provide high velocity (good convection coefficient) and lots of area (q = h*A*delta-T) win. With enough pressure, direct impingement puts a high velocity jet right above the core. Performance drops with a weak pump. Some low-loss designs can make great use of surface area, but don't get great velocity. The real trick is matching a block to a pump without buying more pump than you need. [/b]
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Good info!
So turbulent flow IS achieved in ECUPirate's design? (putting aside the first few cross-channel problem).
I believe that the cross-flow design is probably the best, since it is optimized for high surface. I'm sure that with the right manifold, the coolant flow can be distributed more or less equally.
So myv65, what's your suggestion for a good block?