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# Mailing List Logs for Message no. 1
From: Amonchare max. speed Fri, 12 Feb 93 21:38:16 EST
Before we throw away the old equations, I derive a forumula for maxium speed.
How this doesn't get to envolved for any of you. I got the intermediate
equations from my college physics book. If it does page the end of the post
for the final formula. You find it surprisingly simaliar to the old one.

First I started with an engine of given power P in units of watts. The one
watt can also expressed as 1 (newton * meter)/second. A newton is a unit of
weight and can be expressed as one kilogram * acceleration Remember that a
kilogram is a unit of mass not weight. So that so far we had:

Power(w) = mass(kg) X acceleration(m/s^2) X velocity(m/s)

Since we are talking about a maximum velocity we can assume the power of the
engine is equal to the power neccessary to keep the vehicle moving at that
velocity.
Mass is easy to remove from the right side of the equation. Simply devide
both sides by mass of the total vehicle.

Power(W) mass(kg) x acceleration(m/s^2) x velocity(m/s)
-------- = -------
mass(kg) mass(kg)

the result is:

Power(W)
-------- = acceleration (m/s^2) x velocity(m/s)
mass(kg)

Accelaration in this case is the acceleration the engine must provide to
counter attack the decceleration forces acting on the car. There are many
different forces acting in this way. Wind resistance or drag is a major one
at high velocities. This force can vary from day to day. It depends on
whether you have a tail wind or a head wind, but general increases with speed.
Also this effect can be reduced by "streamlining" the body of the vehicles.
Among some of the other decceleration force is the friction with the road.
Anyway since the actual value of this acceleration is very complicated to
determine I suggest that we use a fixed average value; At least for cars.
Anyway by dividing both sides of the equation by an accelerate ( what ever the
value is) we get:

Power (W) Acceleration(m/s^2) x velocity (m/s)
----------------------------- = --------------------
mass(kg) x acceleration(m/s^2 Acceleration(m/s^2)

or

Power(w)
velocity (m/s) = -------------------------------
mass(kg) x Acceleration(m/s^2)

This is our maximum velocity.

Now lets see if we can make the equation fit a couple of cars. First we got
to assign some values to some of our varibles. First lets start with a luxry
sedan ie a large car no heavy accessories( armor, more body). Mass of these
cars are about 1500 kg in 1993. I believe that with new techinology and light-we
ight
composites of SR this can be reduced to 1300 kg or less. Lets stick with 1300 k
g.
I think Hayden was a little 3000 kg (3.3 tons). This means we have adjust the
car chassis table. Anyway thats mass.
Now engine power. In the same type of cars in power rating s of the
engines range from 100 to 120kw (130-165 hp). Sportier types have more power
but we want to talk average so lets use 110kw.
lets set acceleration equal to one to see how close we get to a

110,000 w 3600 s/h
velocity= ------------ = 84.6 m/s x ------------ = 305 km/h
1300 kg x 1 1000 m/km

cruising speed would be 102 km/h

That worked well let's try another this time a small coupe
mass= 800 kg (1760 lb)
power= 65 kw
again acceleration =1
65,000 w 3600 s/h
max velocity = ------------- = 81.3 m/s x ----------- = 293 km/h
800 kg x 1 1000 m/km

cruising speed of 97.5 km/h

These are the only two examples I tried so far but these two work well,
fianally. Try it out see what you think. Oh, an d disregard my last post
this replaces velocity rules and i found a flaw in the economy equation and
I'm not sure how to convert power into NPU's. I'll work on this and get back
to you unless someone beats me to it.

Oh and here is the kph version of the max velocity formula condensed

power * 3.6
max velocity (kph) = -----------------
mass

-------------------------------------------------------------------------------
Guak
A.K.A. Amonchare
(Michael A. Kauffman)
mak9@******.edu
-------------------------------------------------------------------------------
Message no. 2
From: R Andrew Hayden max. speed (fwd) Mon, 22 Feb 93 06:58:49 CET
This is where we left off, still discussion how to computer engine power
and speed and stuff. I am forwarding the last post on the subject that
was madde to remind everyone what was going on.

Please read over this and comment so we can get back on track.

[> Robert Hayden <] [> ____ Come out, Come out <]
[> <] [> \ /__ Wherever you are! <]
[> rahayden@*****.weeg.uiowa.edu <] [> \/ /
[> aq650@****.INS.CWRU.Edu <] [> \/

---------- Forwarded message ----------
Date: Fri, 12 Feb 93 21:38:16 EST
From: Amonchare <mak9@******.EDU>
To: Multiple Recipients of <KAGE-CAR@*****.nic.SURFnet.nl>
Subject: max. speed

Before we throw away the old equations, I derive a forumula for maxium speed.
How this doesn't get to envolved for any of you. I got the intermediate
equations from my college physics book. If it does page the end of the post
for the final formula. You find it surprisingly simaliar to the old one.

First I started with an engine of given power P in units of watts. The one
watt can also expressed as 1 (newton * meter)/second. A newton is a unit of
weight and can be expressed as one kilogram * acceleration Remember that a
kilogram is a unit of mass not weight. So that so far we had:

Power(w) = mass(kg) X acceleration(m/s^2) X velocity(m/s)

Since we are talking about a maximum velocity we can assume the power of the
engine is equal to the power neccessary to keep the vehicle moving at that
velocity.
Mass is easy to remove from the right side of the equation. Simply devide
both sides by mass of the total vehicle.

Power(W) mass(kg) x acceleration(m/s^2) x velocity(m/s)
-------- = -------
mass(kg) mass(kg)

the result is:

Power(W)
-------- = acceleration (m/s^2) x velocity(m/s)
mass(kg)

Accelaration in this case is the acceleration the engine must provide to
counter attack the decceleration forces acting on the car. There are many
different forces acting in this way. Wind resistance or drag is a major one
at high velocities. This force can vary from day to day. It depends on
whether you have a tail wind or a head wind, but general increases with speed.
Also this effect can be reduced by "streamlining" the body of the vehicles.
Among some of the other decceleration force is the friction with the road.
Anyway since the actual value of this acceleration is very complicated to
determine I suggest that we use a fixed average value; At least for cars.
Anyway by dividing both sides of the equation by an accelerate ( what ever the
value is) we get:

Power (W) Acceleration(m/s^2) x velocity (m/s)
----------------------------- = --------------------
mass(kg) x acceleration(m/s^2 Acceleration(m/s^2)

or

Power(w)
velocity (m/s) = -------------------------------
mass(kg) x Acceleration(m/s^2)

This is our maximum velocity.

Now lets see if we can make the equation fit a couple of cars. First we got
to assign some values to some of our varibles. First lets start with a luxry
sedan ie a large car no heavy accessories( armor, more body). Mass of these
cars are about 1500 kg in 1993. I believe that with new techinology and light-we
ight
composites of SR this can be reduced to 1300 kg or less. Lets stick with 1300 k
g.
I think Hayden was a little 3000 kg (3.3 tons). This means we have adjust the
car chassis table. Anyway thats mass.
Now engine power. In the same type of cars in power rating s of the
engines range from 100 to 120kw (130-165 hp). Sportier types have more power
but we want to talk average so lets use 110kw.
lets set acceleration equal to one to see how close we get to a

110,000 w 3600 s/h
velocity= ------------ = 84.6 m/s x ------------ = 305 km/h
1300 kg x 1 1000 m/km

cruising speed would be 102 km/h

That worked well let's try another this time a small coupe
mass= 800 kg (1760 lb)
power= 65 kw
again acceleration =1
65,000 w 3600 s/h
max velocity = ------------- = 81.3 m/s x ----------- = 293 km/h
800 kg x 1 1000 m/km

cruising speed of 97.5 km/h

These are the only two examples I tried so far but these two work well,
fianally. Try it out see what you think. Oh, an d disregard my last post
this replaces velocity rules and i found a flaw in the economy equation and
I'm not sure how to convert power into NPU's. I'll work on this and get back
to you unless someone beats me to it.

Oh and here is the kph version of the max velocity formula condensed

power * 3.6
max velocity (kph) = -----------------
mass

-------------------------------------------------------------------------------
Guak
A.K.A. Amonchare
(Michael A. Kauffman)
mak9@******.edu
-------------------------------------------------------------------------------
Message no. 3
From: Todd Montgomery max. speed (fwd) Mon, 22 Feb 93 18:08:51 CET
Below are some clarifications on the calculations. These are just meant to
clear up some points I think are a little fuzzy. No flames intended.

> ---------- Forwarded message ----------
> Date: Fri, 12 Feb 93 21:38:16 EST
> From: Amonchare <mak9@******.EDU>
> To: Multiple Recipients of <KAGE-CAR@*****.nic.SURFnet.nl>
> Subject: max. speed
>
>
>
> Before we throw away the old equations, I derive a forumula for maxium speed.
> How this doesn't get to envolved for any of you. I got the intermediate
> equations from my college physics book. If it does page the end of the post
> for the final formula. You find it surprisingly simaliar to the old one.
>
> First I started with an engine of given power P in units of watts. The one
> watt can also expressed as 1 (newton * meter)/second. A newton is a unit of
> weight and can be expressed as one kilogram * acceleration Remember that a
> kilogram is a unit of mass not weight. So that so far we had:
>
> Power(w) = mass(kg) X acceleration(m/s^2) X velocity(m/s)
>
> Since we are talking about a maximum velocity we can assume the power of the
> engine is equal to the power neccessary to keep the vehicle moving at that
> velocity.

To make a car cruise at 50 mph takes about 8 HP (Horse Power). This is
a number I remember from a project. That does not mean a 8 HP engine would
make the car move. When a car is cruising it consumes much less power
than when it is accelerating.

> Accelaration in this case is the acceleration the engine must provide to
> counter attack the decceleration forces acting on the car. There are many
> different forces acting in this way. Wind resistance or drag is a major one
> at high velocities. This force can vary from day to day. It depends on
> whether you have a tail wind or a head wind, but general increases with speed.

Drag Coeeficient (Cd) is a MAJOR effect even at low speeds when Electric
Vehicles are concerned. The Cd of a car can consume a LOT of power if the
car is a brick, and the car is travelling at a relatively slow speed (>20 MPH).

> Anyway since the actual value of this acceleration is very complicated to
> determine I suggest that we use a fixed average value; At least for cars.
> Anyway by dividing both sides of the equation by an accelerate ( what ever the
> value is) we get:
>
> Power (W) Acceleration(m/s^2) x velocity (m/s)
> ----------------------------- = --------------------
> mass(kg) x acceleration(m/s^2 Acceleration(m/s^2)
>
> or
>
> Power(w)
> velocity (m/s) = -------------------------------
> mass(kg) x Acceleration(m/s^2)
>
> This is our maximum velocity.

OK, Contrary to what I have said above, I want something simple. This seems
pretty viable.

> Now engine power. In the same type of cars in power rating s of the
> engines range from 100 to 120kw (130-165 hp). Sportier types have more power
> but we want to talk average so lets use 110kw.

OK, Here is were the HP is taken in. I didn't see it before.
> ------------------------------------------------------------------------------
-
> Guak
> A.K.A. Amonchare
> (Michael A. Kauffman)
> mak9@******.edu
> ------------------------------------------------------------------------------
-

All in all, Good Work
Thanks Amonchare,

-- Quiktek
tmont@****.wvu.wvnet.edu