(thinking out loud)

If one was to have large hoses with = low restriction upstream of the cores, and then put restrictors of the same = size and shape at the outlet of each of the cores, I wonder if the flows = would be close to equal. As long as the most restrictive (highest flow velocity) = point is carefully controlled at the exit of the core, I would think that the relative flows could be closely controlled by adjusting the shape & = size of each of the restrictors. = As long as the Cores were relatively close in flow-rates I would imagine that the = amount of restriction required at the exits would be = minimal.

Just a theory (anyone care to give = it a spin? – or have they already?),

Cheers,

Pete

Eur= opa builder and single rotor = dreamer.

-----Original Message-----
From: Neil Kruiswyk [mailto:neilak@rogers.com]
Sent: = Thursday, January 08, = 2004 = 4:53 PM
To: Rotary motors in = aircraft
Subject: [FlyRotary] = Series vs parralel rads

Ed,

= ; You can put me down for series rads and Jim M as well. Neither one of us could get the = coolant to flow equally through parallel rads. Jim went so far as to add ball = valves on the hot core to try and limit it’s flow. It worked to a degree but = plumbing got very heavy and complicated.

= ; I’ve pondered about this issue and I think there may be a number of factors involved. (Group input is = highly desired) We both used = large hoses for our installations. = 1.5” to the Y’s and 1” from the Y’s to the rads. (Actually, one of us used = Y’s and the other T’s). = I’m wondering if the large hoses after the Y was too little flow resistance = thereby allowing most of the coolant to pass through one rad. I notice Tracey uses smaller = hoses which may increase flow resistance to each rad and provide more of a = balance. I think someone is using AN16 = fittings which is 1” hose but by the time you get through the restrictive = male coupling, the same factors may apply.

= ; Al G. may be able to help me with this one… Assuming a perfect = world… what would the outlet = temperature difference be between series rads vs, parallel. My guess is… if we had 215 degrees coolant = entering the parallel rads and we get 180 degrees leaving the rads, there is a 35 = degree drop, or about a 16.3% drop. = Series rads would give a similar % drop divided by 2 for each. 215 – 8% =3D 199. Then the second rad sees 199 = – 8% =3D 184 (I rounded off the = numbers cuz 1 degree isn’t an issue) By my calculation (which may be out in left field) the difference = is negligible. =

Neil (Giving Rusty = something else to think about)

= ;