Hurricane Speed Test in game

[Crumpp]

it is a function of density altitude

Correct

I'm glad to be corrected on this, preferably in layman's terms without underlined scans

It would be nice if people would not stick to their guns when they are wrong so that such things are not required.

My thinking is that supercharger keeps constant pressure up to the FTH and the mass flow through the engine and power is at maximum at FTH. Below FTH intake air is warmer and hence density at the intake manifolds is lower at given pressure and mass flow and power lower than at FTH, above FTH supercharger can't keep the pressure which reduce mass flow and power.

Let's assume that pressure altitude is keeped constant but temperature is higher. Then the mass flow through engine is reduced due to lower density and less mass flow is needed through supercharger to keep constant pressure due to same reason. The power is, of course, lower at this situtation, however, pressure ratio between manifolds and outside is still unchanged and hence the FTH unchanged as well.

Unfortunately, that is not the case and people continue to argue their point.

[Crumpp]

'Full throttle height' is defined as that altitude above which the supercharger is unable to compensate for the reduced air density and both the BHP and airflow decrease in direct proportion to any further increased altitude.

http://www.keenzo.com/showproduct.asp?ID=3192182

Most of the flight data and engine data you guys argue about is converted to standard day conditions.

On non-standard day's FTH will change true altitude to maintain the same density altitude.

[IvanK]

Courtesy of Klems data tool and his work it has been established that the basic CLOD atmospheric temperature lapse rate is 1.97 deg C per 1000feet (corrected to 2 decimal places). This has now been measured up to 26,000feet. So its only 0.01 deg C per 1000 feet out ... not much and well and truly in the ball park to the ISA value of 1.98 deg C per 1000feet.

[bongodriver]

Originally Posted by IvanK

Courtesy of Klems data tool and his work it has been established that the basic CLOD atmospheric temperature lapse rate is 1.97 deg C per 1000feet (corrected to 2 decimal places). This has now been measured up to 26,000feet. So its only 0.01 deg C per 1000 feet out ... not much and well and truly in the ball park to the ISA value of 1.98 deg C per 1000feet.

You beat me to it but a squad member from the dogz and I have been doing a little experimenting and found something interesting, much like you we have found the lapse rate to be in the 2 degrees per thousand feet but in addition we stumbled upon an element in the FMB that changes the the atmospheric temperature not sure of its function but it is the mission parameters box, there is an option for 'Breeze/Thermal Activity =0/10' with a sliding scale, default seems to be 0 and this gives an ambient temparature of ISA +10, but if the slider is set to 10 the temp almost lines up with ISA, so far no indication that the temps can be brought to an ISA - figure.

I have attached a screenshot of the FMB tool and a graph showing the results of our quick test today.

p.s. I mean to add the test mission was done on a clear day at 12:00 midday, no other tests done to check for diurnal variations.

p.p.s. also added a usefull graph for density altitude calculations.

[Crumpp]

You beat me to it but a squad member from the dogz and I have been doing a little experimenting and found something interesting, much like you we have found the lapse rate to be in the 2 degrees per thousand feet but in addition we stumbled upon an element in the FMB that changes the the atmospheric temperature not sure of its function but it is the mission parameters box, there is an option for 'Breeze/Thermal Activity =0/10' with a sliding scale, default seems to be 0 and this gives an ambient temparature of ISA +10, but if the slider is set to 10 the temp almost lines up with ISA, so far no indication that the temps can be brought to an ISA - figure.

Amazing.....

Almost as amazing as all the "I am real world pilot" on this forum who are testing away, screaming about their favorite gameshape is porked, but don't bother to worry about the atmospheric model or understand it first.

[bongodriver]

Originally Posted by Crumpp

Amazing.....

Almost as amazing as all the "I am real world pilot" on this forum who are testing away, screaming about their favorite gameshape is porked, but don't bother to worry about the atmospheric model or understand it first.

What?

Originally Posted by Crumpp

If that is the case, the atmospheric conditions in the game are standard.

Originally Posted by Crumpp

If it is then that is definative proof the atmospheric model is not agreeing with the Flight Models.

Originally Posted by Crumpp

There is no question or issue here. The atmospheric model is not correct or is using a very non-standard lapse rate.

So how much research did you do before making these assumptions? what is really amazing is how you spew out all this 'know it all' crap thanks to your text books but spend little to no time actually trying to find solutions to a problem.

Still waiting for the evidence you are what you claim to be.

[Crumpp]

What?

I have been talking about the atmospheric model from the beginning. It does absolutely no good to conduct any performance testing without understanding the conditions.

http://forum.1cpublishing.eu/showthread.php?t=32259

Conditions are everything in aircraft performance. That fact is very much on your mind when piloting a real aircraft.

Every take off you calculate V1,V2, Vmcg, Vr, BFL and as well as acceleration checks. All are effected by density altitude.

It looks like you have found the controls to set conditions to standard. That will save time in converting performance under other than standard conditions.

Now that the atmospheric conditions are known, conclusions can be made about specific aircraft performance.