At 75°F, what is the nominal tank pressure for a nitrous oxide hybrid motor?

The nominal tank pressure for a nitrous oxide hybrid motor at 75°F is indeed 750 psi. This value is derived from the physical properties of nitrous oxide as a propellant. Nitrous oxide (N2O) behaves similarly to other gas propellants, where the pressure is influenced by temperature.

At 75°F, the liquid phase of nitrous oxide exerts a pressure that is in equilibrium with the vapor phase. This relationship is critical for the safe and efficient operation of hybrid rocket motors. The pressure must be sufficient to provide the necessary flow of oxidizer into the combustion chamber at ignition and throughout the burn, while also staying within safe operational limits.

Understanding the thermodynamic properties of nitrous oxide is essential, as the nominal pressure can vary significantly with temperature. At higher temperatures, the pressure increases, and at lower temperatures, it decreases. The choice of 750 psi reflects a balance that ensures adequate performance while maintaining safety standards for propulsion systems utilizing nitrous oxide.

Knowing the correct nominal tank pressure is vital for anyone working with hybrid rocket motors, as it informs both the design and operational parameters for the system.