Before model turbine engines hit the market, just about every radio controlled model “jet” was powered by a ducted fan (or a fan spun by a piston engine). People flew these for decades. Now turbines are available. There’s also a whole bunch of high performance electric ducted fan models.

www.bvmjets.com/Pages/electric.html

Maybe you are thinking about the aerodynamics of unpowered bullets.

looks like it flies to me

This craft actually demonstrates perfectly why jet (or jet turbine) engines are so complicated. The air entering the front of the nacelle has to exit with greater thrust than it entered with to compel the craft to flight. As counter-intuitive as it may seem, a closed body design (think single engine Cessna) will generate more lift because of the air flow over the lifting surfaces which is generated by the propeller. This closed body design will rely solely on the thrust derived from the encapsulated propeller to generate enough forward speed for lifting force to be applied to the wings. As the speed of the craft increases, a vacuum will form at the rear of the nacelle. The thrust generated will never exceed the force of the vacuum created at the rear of the thrust nozzle without being forced to exceed the sped of sound. A standard propeller can’t do that, it takes a turbo fan with a significant power source (a jet engine) or after-burners. Forward speed and lifting forces will never be great enough to achieve flight with this design.

I wouldn’t be surprised if this is a pic of a mock-up at an engineering school built specifically to demonstrate these and other principles.

God oh god, please don’t let this become the new air plane on a treadmill debate.

no.