SWTC Update

Ender · Post by **Ender** » 2005-05-29 11:47am

Warships of the Empire

What's the big deal says you? It's been up for years says you? But did some of the entries now include peak power generation estimates says I?

You know, it's odd but I get closer to 2.6*10^25 for the Imperator and thus assume ~ 3*10^27 for the Executor. But Dr. Saxton there estimates it at 1*10^25 and 1.3*10^27 respectively. I wonder what assumption difference we are making.

Hardy · Post by **Hardy** » 2005-05-29 02:26pm

I'm quite sure that you both have your accelerations and specific impulses at 3000 G and 3E8 m/s respectively. Obviously the difference has to do with your estimates of volume and density.

I had never really had checked this particular page out in the past. Interesting read.

Ender · Post by **Ender** » 2005-05-29 03:55pm

Hardy wrote:I'm quite sure that you both have your accelerations and specific impulses at 3000 G and 3E8 m/s respectively. Obviously the difference has to do with your estimates of volume and density.

I had never really had checked this particular page out in the past. Interesting read.

I used .99 actually, that's probably the difference for the Executor. But for the Imperator I scaled down from the DS reactor. So that should be the same unless our scaling has some major differences.

FTeik · Post by **FTeik** » 2005-05-29 05:07pm

Less density of weapons and more space devoted to hangar for the Executor if compared to an Imperator.

I would have given the ISD a power-output of 2.4E25 Watt and the Executor 1.8E27 or 2.7E27 Watt.

Hardy · Post by **Hardy** » 2005-05-29 05:08pm

You know, if you crudely scale up the Venator to 1.6 km and then multiply its power by the difference in volume, you get about 1E25 W. Not at all different from Dr. Saxton's estimate for the power of the Imperator. Perhaps this is deliberate.

And I just learned that it's Imp-er-ae-tor and not Im-peer-ee-ae-tor. I've no idea where I got that from.

Ender wrote:I used .99 actually, that's probably the difference for the Executor.

I'm not quite sure what you mean by that.

But for the Imperator I scaled down from the DS reactor.

There's the difference. Dr. Saxton had simply estimated the mass of the ISD and then multiplied by maximum acceleration to derive force. He then multiplied by the exhaust velocity of c to derive engine power.

Dr. Saxton wrote:~1 × 10^25 W ? (assuming typical warship density and 3000G acceleration)

I find the relative consistency in both methods to be pretty remarkable, though.

Ender · Post by **Ender** » 2005-05-29 07:24pm

Hardy wrote:You know, if you crudely scale up the Venator to 1.6 km and then multiply its power by the difference in volume, you get about 1E25 W. Not at all different from Dr. Saxton's estimate for the power of the Imperator. Perhaps this is deliberate.

Well, power should be proportional to volume, so that makes sense.

Ender wrote:I used .99 actually, that's probably the difference for the Executor.
I'm not quite sure what you mean by that.

Exhaust velocity, 99% of C. however I just realized that it doesn't matter what I used for the exhaust velocity since I didn't calc it that way. For a consant exhaust velocity and similar peak accel the diferenece in peak power will be the same as difference in mass.

But for the Imperator I scaled down from the DS reactor.
There's the difference. Dr. Saxton had simply estimated the mass of the ISD and then multiplied by maximum acceleration to derive force. He then multiplied by the exhaust velocity of c to derive engine power.
Dr. Saxton wrote:~1 × 10^25 W ? (assuming typical warship density and 3000G acceleration)
I have to wonder how he determined the mass then. the simple X% solid times iron times volume doesn't cut it as it doesn't account for fuel and reactants.

I find the relative consistency in both methods to be pretty remarkable, though.

Confirmation of results through alternate means

Hardy · Post by **Hardy** » 2005-05-29 11:46pm

Ender wrote:Exhaust velocity, 99% of C.

I see. It's easier just to go with 3E8 to get a rounder number.

For a consant exhaust velocity and similar peak accel the diferenece in peak power will be the same as difference in mass.

So you're saying that the difference in results has to do with difference in mass estimation, right?

I have to wonder how he determined the mass then. the simple X% solid times iron times volume doesn't cut it as it doesn't account for fuel and reactants.

Dr. Saxton may have already taken that into account. Working backwards, it turns out that the density of the ship is greater than lead.