[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: Spark length dependence on air pressure.



Original poster: "Gerry  Reynolds" <gerryreynolds@xxxxxxxxxxxxx>

Hi Jim,

Another thought. Instead of using a look up table (probably the most accurate) one could use the following exponential equation using 18000 feet as the half pressure point. Note, I use "2^" cause this is the half pressure point and this equation would predict that at 36000 ft the pressure would be 1/4 of sea level and I dont know if this is true. Im being somewhat lazy here cause I dont want to look it up.

Gerry R.

Pabsolute = Psealevel_STP *  2 ^ (-density_altitude/18000)

Original poster: Jim Lux <jimlux@xxxxxxxxxxxxx>

Except that density altitude isn't what he wanted. He needs actual density ratio. You'd still need to know what altitude corresponds to what density (numerically).