Commercial and US Government Launch Vehicles > ULA - Delta, Atlas, Vulcan

ULA Innovation: Integrated Vehicle Fluids (IVF)

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--- Quote from: Designvis on 04/07/2015 03:39 pm ---IVF works beautifully in concert with fuel cells and solar electric systems.  You let those systems handle long-duration low-level power demands and turn IVF on when you need to do heavy lifting. This enables them to be compact and light since they don't have to handle peak loads.  You can even eliminate dedicated controllers and power processing units which are major elements in the cost of those systems. The mission transition time is dependent on tank thermo, power level and other stuff but its usually after many days. 

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I didn't understand this bit about "mission transition time." What exactly happens "after many days?"



--- Quote from: the_roche_lobe on 04/09/2015 11:48 pm ---Is the twin engine setup shown in those simulations just notional or is the first flight actually going to use a twin engine Centaur? Would a single engine Centaur need only one ICE?

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2 pods with thrusters are required on every stage.  The numbers of each item in the pods is determined by the redundancy scheme they want to employ.


--- Quote from: LouScheffer on 04/08/2015 02:51 pm ---An aluminum block might be fine here.  Even the Vega came with a 50,000 mile (~80,000 km) warranty.

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That's OK then. Super Synchronous goes to ~80,000 km.

Cheers, Martin


--- Quote from: deltaV on 04/07/2015 10:31 pm ---
--- Quote from: jongoff on 04/07/2015 09:48 pm ---This engine runs so rich (GOX/GH2 has an amazingly wide flammability range) that I think it might not even need steel sleeves, though I might be wrong.

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Do you know what mixture ratio it's designed for?

I believe Earth ICEs usually run pretty close to stoichiometric but they're kept cool by all the nitrogen in air. Even to match typical Earth ICE temperatures you'd need tons of unburned hydrogen so I'm skeptical of the no-steel-needed conjecture (but am not an engineer). It's certainly plausible that they might run it that fuel-rich so I'm not saying it's wrong, just I'd like to see more evidence before I'm convinced.

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From page 5
"Approximately 2 kg/hr of hydrogen and half that amount of oxygen will be consumed at low power settings"

I make that 16x richer than stoichiometric.

An ICE stage without main engine ie no RL10 could be used as a fuel tanker. Deliver it to orbit as payload on any LV eg FH,D4H. Once in orbit it can wait for a upper stage which needs topping up or deliver its self to a fuel depot using small thrusters. One of the papers stated the ICE driven pumps could feed a 500kg thrust engine, which should be enough for station keeping of 20mt-40mt plus enable it to be deorbited once empty.

ULA had an article on fuel depot article where a SLS class LV was launched with upper stage tanks partially loaded with LOX but fully loaded with LH. It topped its tanks up with LOX from a fuel depot before going to BLEO. The idea was to enable it to carry a heavier payload. The reasoning behind full load of LH was a) it was lite and b) it was harder to store in fuel depot without boiling off. For this situation the ICE stage would only carry enough LH for station keeping. 


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