|From:||"Michael A. Kauffman" <mak9@******.EDU>|
|Subject:||Re: DSF and more|
|Date:||Sat, 3 Apr 93 14:53:53 EST|
I stated earlier.
Engines - Power, mass fine (see below)
The same for Cruising Speed, Maximum Speed, Effiency (IC), and Effiency (MF).
> Effiency (Elec) = (2000/Mass) km/PF Effiency (ImpElec) = (1000/Mass) km/PF
> I propose these two values for electric economy because in RBB the ImpElec
>engines are more powerful than Elec, but burn up "fuel" twice as fast.
This looks good. (It is very close to what I proposed awhile back)
> Now does
>anybody have ideas on how different the PU should be on MF and ImpElec? RBB
>indicates a +25% to power for ImpElec and a -14.3% power for Multifuel.
I suggest we increase the size/mass of the MF engine. This will mean that in
order to get the same P/M ratio for the car one will have to put in larger(BVU)
engine. If he is limited by space, he'll have to settle for a lower P/M.
This is just another way of saying decrease the power of MF engines, but I
find it easier to look at this way.
As for formulas, based on our size to power relationships and RBB, I come up
with the following:
size(IC) = sq. root (Power) or Power = size^2
size(MF) = 1.1 * sq. root (Power) Power = size^2/1.2
size(IE) = 1.2 * sq. root (Power) Power = size^2/1.4
size(El) = 1.3 * sq. root (Power) Power = size^2/1.7
I know we decided ( after some discussion) that IC and Elec. where
approximately the same size/mass. I we should reconsider that. FASA obviously
didn't think so. I propose that ImpE and IC have the same size/mass and that
MF and Elec are larger and more massive. That changes the formulas as follows:
IC, MF are the same as above
size(IE) = sq. root (Power) or Power = size^2
size(El) = 1.2 * sq. root (Power) Power = size^2/1.4
what do you think? Does this adequately answer Carter's question?
I also have another question. Should there be power limits on MF and Elec
engines? I ask because in RBB there are no Elec engines for large vehicles
(trucks, vans,etc) and there are no MF engines for motor cycles. Perhaps no
Elec engines > 300 kW and no MF engines < 50 kW. Any thoughts?
Signature/Handling - no problems.