DERG:
MIL-PRF-7808 is a lubricating oil that must meet the following spec: Flash point 210
° C (~ 410
° F). I appreciate that an ambient pressure less than atmospheric would likely induce a flash to vapor at lower temps.
But lubricating oil in a jet engine is a fluid / liquid, under pressure.
Why do you feel that a fluid under pressure will flash?
I guess my question to you is: at what point when operating at cruise altitude do you believe that the lubricating oil is operating at ambient (20K feet, 30K feet 35K feet) pressures? The oil system remains under positive pressure, and contained ... or it leaks and sprays oil and you run out post haste and the issue of "flash" is far less than it is oil starvation.
I'll bite.
How is the application of Kelvin' Gas Laws utile in our discussion of oil properties when we are discussing a closed fluid circulating system under positive pressure? Is it your position that the lube is sprayed/applied by the system, before scavenge, to components that are operating at ambient pressure for the altitude?
Happy to understand your point better, if you'll elaborate a bit.
Thanks.