What is the fuel and oxidiser used in the V2 rocket
fuel - 74% ethanol/water mixture
oxidiser - liquid oxygen (LOx)
How was combustion temperature in V2 lowered to a tolerable level
- used water in fuel to reduce temp
- used regenerative cooling (fuel to cool combustion chamber)
How did soviet R7 improve pressure and temp tolerances
- used corrugated sheets between thin inner walls and steel outer walls
- then used regenerative cooling through walls
- both helped tolerate higher temp and pressure more
Write down heat flux equation
Q = k (Twg - Twl)/L
Q - heat flux
k - heat conductivity
Twg - temp wall gas (comb. chamb)
Twl - temp wall liquid (outer wall)
Which rocket is the most used space launcher and why
- Soyuz space rocket
- low cost and highly reliable
- 20x cheaper than space shuttle launch
- used ORSC
How did F1 engine in Saturn V rocket overcome combustion instability
- used four smaller combustion chambers around a central core
Pros and cons of using multiple combustion chambers
pros
- increased suitability
- higher compression ratios
cons
- more weight
- more noise
Explain what LES (launch escape system) is
Used if failure in takeoff. This module will be launched separate from rocket and then parachutes will carry it back down away from launch site.
4 parts:
- launch abort system
- crew module
- service module
- space craft adapter
Discuss why you would use ejector seats rather than LES
- keeps launch weight low
- used in systems where propellant explosion in launch was smaller so astronauts don’t have to travel that far away from launch site to be safe
Explain why ocean launch is good at the equator
- reduced risk of launching over populated areas
- absence of range conflicts with other launch systems
- equator great to reduce thrust requirements for payload
Why are ORSC systems harder to design
Because they provide higher efficiency due to elevated temperatures. At these temps, normal metal may melt or corrode
Why should Kerosene not by used in FRSC
Kersone is very dense and can be left as residue in valves.
Also high temperature combustion which means containing is much harder
Draw both FRSC and ORSC
pic1
pic2
What is a full flow staged combustion cycle. Which engine plans to use this
- Space X raptor engine
- eliminates the fuel-oxidiser turbine interseal
- lower pressure requirements in pumps
- can increase combustion chamber pressure
Pros and Cons of using liquid methane
Pros
- Better specific impulse
- Better cooling capabilities
- No/less residue in pipes
- No need for extra infrastructure and cheaper
- Can be produced on Mars from CO2 and Water
Cons
- Slightly lower bulk density than RP-1
- Slightly overall heavier as requires more oxygen to burn than RP-1
Pros and cons of reusable rockets
Pros
1. Fuel cost only 0.3% of total so saves on manufacturing cost
Cons
- Payload possibly reduces by 30%
- Added cost of: development, manufacturing, recovering, possible refurbishment
- Needs at least 10 re-uses to make it economically even
- Market for it might not be large enough
Why does the bloodhound SCC use 3 different engines
- EJ200 jet engine: go from 0-350mph
- hybrid rocket 350-1000mph
- Supercharged jaguar v8 engine used as fuel pump
