Salami Rocket

WTF?

Hybrid rocket propulsion system conceptual overview

Nomen est omen. Salami rocket is about building a hybrid rocket with a gaseous oxydizer and salami as propellants.

Oxydizer

I'd prefer N₂O over O₂ because although N₂O carries a lot of conjectural inert nitrogen (64%) oxygen is much harder to handle (tank filling, storage & injection). Additionally the nitrogen, though not participating in combustion, raises the fuel erosion rate and cooles the nozzle enough to reuse it many times.

Fuel

Salami: High efficency hydrocarbon based fuel ;)

Simulation

Im using RockSim to simulate the flight stability of the rocket. The behaviour of the N₂0/Salami hybrid motor is simulated by an external model programmed in C++.

Draft

• Run Tank: A light-weight container for the oxydizer capable of sustaining enough pressure
• On/Off Valve: Enables/Disables oxydizer flow.
• Throttle Valve: A valve to allow precise regulation of the oxydizer flow from the run tank to the combustion chamber.
• Injector: Aids in vaporizing the (still) liquid oxydizery.
• Combustion Chamber: Where the oxydizer/fuel mix burns. Additionally to pressure (same amount as for the run tank) it has to sustain heat.
• Nozzle: An opening that dramatically accelerates the hot gas escaping the combustion chamber.
• Ignitor: Preheating the fuel and initializing combustion.
• Shell: Protecting the motor
• Recovery System (parachute): Enables slow decent after burn-out for safety and reusability
• Tail camera: It's all about the nice view
• Altimeter: Measurement concludes the fate of the cat
• Electric beacon: Transmits a signal to ease finding the landing site.

Shopping list

All parts directly participating in the combustion would have to sustain at least 51 bar (vapor pressure of N₂0 at 20°C) but for reasons of safety i assume 100bar as the minimum.

Run Tank

Smart Parts C02 aluminium tank for paintball guns with on/off valve.

• Capacity: 591ml (20 oz)
• Connector: 1,27cm (1/2")
• Max Pressure: 200bar
• Price: 45€

On/Off Valve

No separate valve needed since the proposed CO2 tank has it built-in.

Throttle valve

An adjustable throttle valve (Stasto VRB-030) intended for use in hydraulics.

• Connector: 1,27cm (1/2")
• Flow rate: 45 l/min
• Working pressure: 350 bar
• Price: 30€

Injector

Probably custom made or this one -> SKR-54UC

• Diameter: 54mm
• Price: 53 €

Combustion Chamber

C02 aluminium tank for paintball guns without on/off valve.

• Capacity: 591ml (20 oz)
• Connector: 1,27cm (1/2")
• Max Pressure: 200bar
• Price: 14€

Nozzle

SKR-54NZL graphite nozzle

• Diameter: 54mm
• Price: €35

Ignitor

None selected yet.

Shell

A nice design proposal by mactux. Exact specifications & blue prints yet to be made.

Recover System

None specified/selected yet.

Links

• Basic concept of hybrid rockets at wikipedia
• Excellent tech papers on calculating, planing and building hybrid rockets
• Very helpful articles of Richard Nakka about his experimental rockets
• Rocketry know-how DB (DE)