Re: [ERPS] TPS options

[Donald Qualls]

Pierce Nichols wrote:
>
> Hrm... I'm inclined to take Gary's ideas with a grain of salt,
> but it passes the smell test. The question in my mind is how much more
> water, of course. I don't think you need (or would want) a grid of tiny,
> precise holes, but instead a material of a define porosity. It seems to
> me that you could source a metal foam to fit the bill.

The problem with a metal foam is that there's no reliable way to ensure that every pore gets adequate flow without pumping much more water than most of the pores need. If you have reasonably precise control over the pressure drop across each orifice (and you should, will drilled holes), you can design a manifold that will keep the flow from each hole within, say, 5% of the nominal design figure -- and a manifold is a lot cheaper and lighter than a whole bunch of metering valves, one for each segment of a foamed skin.

For that matter, it's probably possible to get good protection where it's needed most with a single orifice -- think in terms of the forward gas jets that are used in the new generation of high-speed cavitating torpedoes. A similar high velocity jet of water could interact directly with the stagnation point, where heating is greatest, and prevent the hottest region from transferring heat into the skin and structure. What I don't know is how much more water that would require, compared with a network of small holes to form a cooling film, or whether the combination of extra water and higher pressure feed system would be lighter than a complex manifold and more robust skin.

--
What you own is your own kingdom, what you do is your own glory.
What you love is your own power, and what you live is your own story.
-- Neil Peart, 1976

Donald Qualls, aka The Silent Observer NAR # 70141-SR Insured
Rocket Pages http://silent1.home.netcom.com/launches.htm
Telescope Pages http://silent1.home.netcom.com/astronomy.htm
Lathe Pages http://silent1.home.netcom.com/HomebuiltLathe.htm

Opinions expressed are my own -- take them for what they're worth
and don't expect them to be perfect.

_______________________________________________
ERPS-list mailing list
[EMAIL PROTECTED]
http://lists.erps.org/mailman/listinfo/erps-list