Dreaming a bit, my design would be a natural for pressurization.
It has a single-piece canopy that covers the complete fwd fuselage and slides forward for egress, with the top half Plexiglas or lexan and the bottom half composite, so it looks pretty close to the picture above, but much wider and longer. Except for the sliding mechanism and aero loads it's not structural, thermal deformations are coped with by longitudinal expansion and a rigid "rear ring" with the locking mechanism. The flexible rails is only for sliding fwd/aft, the rear "ring" and air inlet in the nose will keep it in place during flight.
An alternative construction that sprang from this thread is to make the complete sliding part out of plexiglass or Lexan to avoid the problems of thermal elongation between different materials.
You barely see windows on pressurized aircraft with significant curvature (except for some fighters and the Cessna P210), which leaves me wondering whether pressurizing a window (compared to just loading it in bending as most pressurized aircraft seem to do) is feasible.
Assuming a 4ft diameter, circular cross sections and a 1000 PSI load limit (fatigue limit for Lexan) with a 15 PSI pressure differential (7.5 difference times safety factor) the minimum thickness would be on the order of 3/16", thus quite feasible. Naturally, the connection between window and the lower composite pressure vessel is critical.
Am I overlooking something, or is this perfectly reasonable?
How about Lexan/Plexiglass strength at low temperatures?
It has a single-piece canopy that covers the complete fwd fuselage and slides forward for egress, with the top half Plexiglas or lexan and the bottom half composite, so it looks pretty close to the picture above, but much wider and longer. Except for the sliding mechanism and aero loads it's not structural, thermal deformations are coped with by longitudinal expansion and a rigid "rear ring" with the locking mechanism. The flexible rails is only for sliding fwd/aft, the rear "ring" and air inlet in the nose will keep it in place during flight.
An alternative construction that sprang from this thread is to make the complete sliding part out of plexiglass or Lexan to avoid the problems of thermal elongation between different materials.
You barely see windows on pressurized aircraft with significant curvature (except for some fighters and the Cessna P210), which leaves me wondering whether pressurizing a window (compared to just loading it in bending as most pressurized aircraft seem to do) is feasible.
Assuming a 4ft diameter, circular cross sections and a 1000 PSI load limit (fatigue limit for Lexan) with a 15 PSI pressure differential (7.5 difference times safety factor) the minimum thickness would be on the order of 3/16", thus quite feasible. Naturally, the connection between window and the lower composite pressure vessel is critical.
Am I overlooking something, or is this perfectly reasonable?
How about Lexan/Plexiglass strength at low temperatures?
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