2009-12-20

Correction to FPEA figure and consumption estimate

I once calculated the MAX III flat plate area equivalent area to be 0.336 sq ft. My latest study for the two seater with a small engine gives me only 0.58 sq ft or less for a FPEA..maybe only 0.55 sq ft ( this does not include the tailwheel ).

This leads to interesting assumption hypotesis of the best possible fuel consumtion with Jabiru 5100.

Lars Giertz had NASA data of his VmaxProbe having 0.45 fpea and being able to reach 300 mph at 80 hp. http://www.webcamsue.nl/vmax.html#shedo

I think we could assume Vasama II could do 300 mph at 100 hp if fpea is .55.

Jabiru burns 26 l/h at 75% ( 135 hp ).

Other options;

Comparison between o-200 ja ULS 912:sta; http://wiki.answers.com/Q/Fuel_Consumption_of_a_Continental_0-200

O-200 consumes 6 gal/h http://www.mail-archive.com/coupers@topica.com/msg14611.html

O-360 burns 38 l / h ( 10 gal/h or less ).

Let us assume Vasama II according to NASA via Giertz link could go 350 mph at 135 hp and uses 26 l/h. This would mean 2.3 l/ 100km /person using Jabiru 5100 engine at 563 km/h speed.

This would not only mean very fast travelling but economy 45% better than a LearFan 2100 which already beats Smart Jet by 30%.

So I think there is a good reason to go on with this assumption that 2-seater is more economical by than a single seater and if Giertz was right this will be a true sensation when correctly build and designed.

I also assume that at full burn at 180 hp ( Jabiru 5100 max power ) Vasama II could go 380 mph. Being by far the fastest ac in its class. Giertz plane was estimated to go 240 mph at 50 hp. ( 30 hp increase gave 61 mph increase in speed ). I assume 50 hp increase could yield 30 mph increase ( seriously I am very moderate here ).

I don't thin this can go 412 mph like TIO-540 powered NXT; http://www.pilotfriend.com/experimental/acft5/1.htm

All in all possibly better mileage at 250 mph ( 75% power) using a ULS 912 could be obtained.

If we assume that ( regarding the FPEA ) that Rotax uls 912 at 100 hp uses 19 l/h can go 300 mph the consumption would be just under 2 liters per person/ 100 km.

So I get the feeling not only endurance record but also speed record could be obtained with this two seater; http://records.fai.org/general_aviation/current.asp?id1=17&id2=1

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