Hi Mando,
I am new here but wondered if you had looked at Coanda effect. Coanda jets are generated by blowing a moderate to high pressure gas (such as air) or liquid through a narrow slot over a surface which in some cases may be convexly curved.
The jet runs tangent to the surface and can circulate around 180° bends. This we call the primary jet. Our methods are able to cause the jet to recirculate around 360°. The Coanda jets are never laminar like the flow over an aircraft wing or fan blade. The jets are always highly turbulent. The jet is composed of myriads of localised eddy currents. The speed of the air in the swirling or rotating currents is far higher than the linear velocity of the whole jet stream itself.
Pressure is related to speed as you are now aware of. A round jet issuing from a nozzle entrains ambient air due to its high velocity lowering its pressure which attracts the ambient air by collision and entrapment of molecules. Coanda jets are ejected from slots and then traverse a hard surface or wall. They are sometimes called a wall jet. This wall after the slot creates a non-symmetrical nozzle.
The velocity of the jet immediately evacuates the molecules between it and the wall. This low pressure region cannot be relieved by ambient inflow as ambient air is on the other side of the jet and so the jet quickly deflects toward and runs tangent to the wall. The average pressure across a Coanda jet is lower than the average pressure across an unbounded round jet. This means that the average velocity at any point in the Coanda jet is higher than in a conventional jet at the same distance from the slot. It follows then that the pressure is lower at any comparable distance from the slot and the momentum and mass flow are higher at the same points. Flow augmentation by entrainment of ambient air is also greater than with a conventional jet because of the pressure gradient caused by the proximity of the hard surface (the wall) tangent to the jet and this is a more efficient means of momentum transfer than mere molecular collision and entrapment as with conventional jets. This system should be able to get a fully laiden 747 off the ground in 350 meters, the best shape in experiments have been spheres.
cheers Farmer
I am new here but wondered if you had looked at Coanda effect. Coanda jets are generated by blowing a moderate to high pressure gas (such as air) or liquid through a narrow slot over a surface which in some cases may be convexly curved.
The jet runs tangent to the surface and can circulate around 180° bends. This we call the primary jet. Our methods are able to cause the jet to recirculate around 360°. The Coanda jets are never laminar like the flow over an aircraft wing or fan blade. The jets are always highly turbulent. The jet is composed of myriads of localised eddy currents. The speed of the air in the swirling or rotating currents is far higher than the linear velocity of the whole jet stream itself.
Pressure is related to speed as you are now aware of. A round jet issuing from a nozzle entrains ambient air due to its high velocity lowering its pressure which attracts the ambient air by collision and entrapment of molecules. Coanda jets are ejected from slots and then traverse a hard surface or wall. They are sometimes called a wall jet. This wall after the slot creates a non-symmetrical nozzle.
The velocity of the jet immediately evacuates the molecules between it and the wall. This low pressure region cannot be relieved by ambient inflow as ambient air is on the other side of the jet and so the jet quickly deflects toward and runs tangent to the wall. The average pressure across a Coanda jet is lower than the average pressure across an unbounded round jet. This means that the average velocity at any point in the Coanda jet is higher than in a conventional jet at the same distance from the slot. It follows then that the pressure is lower at any comparable distance from the slot and the momentum and mass flow are higher at the same points. Flow augmentation by entrainment of ambient air is also greater than with a conventional jet because of the pressure gradient caused by the proximity of the hard surface (the wall) tangent to the jet and this is a more efficient means of momentum transfer than mere molecular collision and entrapment as with conventional jets. This system should be able to get a fully laiden 747 off the ground in 350 meters, the best shape in experiments have been spheres.
cheers Farmer
