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.

Mike Kauffman

AKA Amonchare