Design Engineer — AVROS Rocketry
Designing a safety-critical piston for the propellant pressurisation system of a reusable liquid rocket engine, including O-ring gland sizing to withstand 500–800 psi.
I design the piston that physically separates IPA and N₂O inside the propellant tank assembly of a reusable liquid rocket engine. It is a safety-critical part: if the seal between the two propellants fails, they meet somewhere they are never meant to meet.
The design starts as hand calculation and progresses into parametric CAD in Onshape, so the geometry stays driven by the numbers rather than by what happens to look right on screen.
The seal work is the core of it. I develop the O-ring groove sizing — squeeze factor, stretch, and volumetric gland fill — to hold across a 500–800 psi range. Getting gland fill right matters because an over-filled groove has nowhere to displace to under pressure, and an under-squeezed one leaks.
I document the sizing process through structured calculation records, so each dimension can be traced back to the assumption that produced it. That makes the design verifiable by someone else and reusable on the next iteration instead of being re-derived from scratch.