I have been recently thinking about a conceptual VTOL aircraft thruster that should generate lift through the use of a drag force and I am very curious to know if such a thruster has ever been built and tested on a VTOL aircraft.
The basic principle of it would be a drag force acting upon the top surface area of an airfoil that would be partially embedded within a vertical pipe. The drag force (low air pressure area) would be created using pressurized air that would exit out of the vertical pipe at a high velocity and would flow around the top surface area of the embedded airfoil.
The outside ambient air pressure pushing against the exterior surface of the reducer section of the vertical pipe should result in lift/upward thrust. This would be due to there being an atmospheric air pressure imbalance between the outside surface area of pipe's reducer section and the top surface area of the airfoil.
To help illustrate and explain how this VTOL thruster would work, I have created a couple of CAD drawings and have posted them below.
(Note: I want to point out that four screws are being used to secure the airfoil to the vertical pipe, and that the airfoil is colored orange to help it stand out from the rest of the thruster.)
I have spent many hours searching VTOL/drone manufacturers' websites and aviation historical websites on the Internet for a VTOL thruster design similar to this one but have not found one yet.
Has there ever been a VTOL aircraft thruster that generated lift through the use of a drag force?
Based on user FreeMan's comment below in which he suggested that a better design would be to have two very smooth curves directing a pre-divided air flow up and down, I redesigned this VTOL thruster to incorporate this design improvement.
In this new design, the airfoil in the top nozzle is more streamlined and the bottom nozzle is positioned within the bottom pipe so that air will have a harder time entering into the bottom nozzle due to turbulent airflow, causing a slight airflow restriction.
I am thinking that this slight airflow restriction will result in more of the inlet pipe's air mass to flow out of the top nozzle which hopefully will result in what I want to achieve, which is approximately 50% of the inlet pipe's air mass to exit out of the top nozzle and approximately 50% of it to exit out of the bottom nozzle.