Would a 2nd row of distributed props on the rearward wing of a biplane with 25% gap and 150% negative stagger increase the efficiency of a biplane ULTRALIGHT, 25MPH, Re 500K? ( rear wing is 25% lower than forward wing, 150% rearward)
Both wings would have distributed propulsion from several props along their span in tractor configuration.
Forward wing props see a prop inlet speed of V1, or aircraft speed.
Forward wing sees V2 ( exit speed of prop), (assume an increase in speed of 50%, based on prop size, Hp using prop formula) V2=150%V1
Calculate forward wing size based on 150%*V1*k1
k1= efficiency/coverage factor of Wing1
Props of 2nd (rear) wing would have a inlet speed of V2, but an exit speed of V3 ( assume another 50% increase)
2nd wing sees a speed of V3=150%V2=150%(150%V1)=225%V1.
Calculate rear wing size based on 225%*V1*k2
k2=efficiency/coverage factor of Wing2
An interesting note: average leading edge airspeed over wings is (150%+225%)/2=190% of aircraft speed!! ( if this proposed theory is correct)
Is this correct, at least conceptually? See side view of configuration below.