Characteristic Equation of Aircraft Cabin Pressure Control System

Think you need to know square footage of the atmosphere to be pressurized to a density of typically 8 thousand feet, and do compression pump allowing cruise for a jet airliner at FL 3 plus.

The equations may come from others. All I remember now is that what is standard is a cabin pressure of 8 thousand feet regardless of Mean Sea Level altitude.

The article in wikipedia gives the full information:

"Pressurization is essential over 3,000 metres (9,800 ft) to protect crew and passengers from the risk of hypoxia and a number of other physiological problems (see below) in the thin air above that altitude and increases passenger comfort generally. "The outflow valve is constantly being positioned to maintain cabin pressure as close to sea level as practical, without exceeding a cabin-to-outside pressure differential of 8.60 psi." At a cruising altitude of 39,000 feet (FL 390), a Boeing 767's cabin will be pressurized to an altitude of 6,900 feet. "

Consider as source the air out of cabin and the pressure difference as the parameter you should regulate. Your load is the cabin volume with its internal pressure. This means that the compressor must give the necessary amount under the worse condition and compensate for the losses which depend on the quantity of CO2 expelled by passengers. I would suggest you work in air massic flow and not in volume since if you work with volumes you can make errors. This is always recommended when working with compressible fluids.

Please explain air massic flow. I had wondered as I wrote about vapor factors that would influence air density and quality. I was also going by memory.

Unless regs have changed you are not required to breath oxygen in an unpressurized aircraft as PIC, pilot in command, below 12,500 feet MSL, (Mean Sea Level). I forget some of the regs, but do think that over 12,500 feet you can fly for 30 minutes without oxygen.

When you have to deal with flows of compressible fluids at different pressures it is better to use the massic flow in kg/time unit. It gives a better control of involved energy.

I would contact aircraft manufacturers and ask them for their, "Characteristic equation of the Aircraft Cabin Pressure Control System".

I have no idea.

I just need mathamatical equations for Pressure control on an aircraft... Thanx

What, you thought we would just hand over your research work for you to use? Equations without knowledge as to what the equations mean will be quickly ripped apart by a good educator, particularly a thesis. Hit those books and web sites for the raw information. Keep us in mind if you need any translation. But don't expect us to do the work for you, it won't help you.

You are presumed to be able to write by your self the equation if you have the necessary information. If not then you are not the right person to make the simulation!

In fact in my explanation you have every detail you need for the equation.