From: vince@offshore.ai (Vincent Cate)
Newsgroups: sci.space.tech
Subject: Re: Heat Sink Heat Shields
References: <5dcb47db.0310011151.51d744ce@posting.google.com> <9186edb5.0310012120.758e3a2a@posting.google.com> <5dcb47db.0310030723.3b2688dc@posting.google.com> <9186edb5.0310042111.41efb20c@posting.google.com>
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I ran sample 51 with different L/D and different CD and the results
for the 12 sq-meter case (middle one in sample) are in the table
below. This sample has a 1000 Kg beryllium heatsink on a capsule
with a total mass of 4,000 Kg (so 25% of capsule mass is heatsink)
reentering from 7.7 km/sec.
L/D CD Tmax C BBH2O
0.4 1 986 939
0 1 793 621
0 2 591 451
0.4 2 771 672
So one big question I have is what is the right CD (coefficient of drag)
for an Apollo style capsule on the way down? Henry, do you know?
The BBH2O is the amount of heat expressed in terms of the number
of Kg of hot water that we could boil.
The Tmax C is the max temperature the heatsink gets to. Note that
it does some radiating of heat.
This shows that with some lift (L/D of 0.4 here) you get more total
heat (like 51% more).
I would love to know some real experimental values for Tmax, CD,
type of material, mass of heatsink, L/D, drag area, etc so I
could see how close I am.
Anyway, the Java applet is at http://spacetethers.com/spacetethers.html
And example 51 and 52 are the Beryllium heatsink ones.
-- Vince