can compressor stage of the hi bypass turbofan replace entire fuselage nosecone
Asked Apr 9, 2012, 06:03 AM
can the fuselage of a jet aeroplane at its nose cone end be replaced by an intake cowel for the fuselage's entire crosssection and then have that cowel feed the air direct to an upfront 40:1 LP IP HP 3 stage compressor of a turbofan engine that has its combustion and nozzle stages still located at the tail end. The nose cone end compression stage , then chutes the HP air to a pair of a hi bypass turbofan combustion engines that are behind the plane not alongside it,at the rear of the fuselage. in essence making the engine the length of the fuselage and removing the positive pressure at the nosecone by giving the fuselage a negative pressure zone ahead of the plane that eliminates all fuselage drag.
in other words is there already a negative pressure ahead of the current intake cowel of high bypass turbofan engines that could be maintained by splitting the engine into compressor stage at the fuselage front end and a combustion and exhaust at the rear end of the fuselage
if that is possible then the fuselage crossection can be increased with no drag being created and the plane as a twin deck passenger liner could then put 6 pasengers per row on top and bottom deck compared to just 4 per prow for a long slim single deck plane and that extra width and height could more than half the plane's length to under 12 metres
with no fuselage drag or engine drag the short plane could have a 3 wing box short wing span asymmetric aerofoil system that supports the compressor stage and avionics on wing box 1 at the planes front end, the passengers and fuel in wing box 2 in the middle of the plane on longer broader wings and wing rear could be the combustion and nozzle weight of the engines carried by wing box 3
The fuselage at the air intake could have front wings set on top of the plane the next set oif wings as the middle wings under the plane and tail wings high up on the tail so none of the wing pairs suffer downstream turbulence from thoise ahead of it . The small distances between supports when landing could enable 50% CNRP in its build to reduce MTOW to under 22 tonnes for 10 tonnes of passenger and baggage and with twin 16000 lb thrust (72KN) engines may only need only 2T of fuel to travel 1600 miles ( 2500 km) that about 1.2L/(100 passenger kms). compared to 3 or 4(L/100 passenger Km) for existing 100 seater plane design.
So the question is if you increase the intake cowel area of a turbofan hi bypass engine from 1.2 sqm to say 7sqm and put it at the front of the plane to replace the entire nose cone of teh fuselage can that intake maintain negative pressure ahead of the plane and hence eliminate all fuselage drag...what do the numbers suggest... is where I am at naive or can such a split convert the fuselage of the plane into its engine.
As a compromise would having some of the intake air at the nose end bypass the compressor and be piped at ambient pressure and velocity straight to the rear engines allow the remander of terh air to enter the compressor stage so only 4 to 5 sqm of air per engine is needed to maintain negative pressure ahead of the plane.
if rleocationof the intake and compressor stage isfeasible the argument for circular cross section planes may disappear and small jet planes would simply chute their air between the inner and outer skin of their near rectangular cross section straight to the turbofan at the rear with the pilot housed in the narrow slit that is created at the twin flows of air to his left and right in the plane's skin are sent as compressed air streams to the rear mounted engine.
can the plane become just an engine with wings with passengers in the gaps between the compressor and the combustion stages