The Coanda effect refers to the characteristic of flowing fluids to follow the curvature of a convex surface instead of continuing in the original direction of flow. Nowadays this effect is applied in various fields of engineering, e.g. to increase lift in air travel, to control the air flow in air conditioning or as a pneumatic logic element in industrial control systems. Pneumatic logic elements have the advantage that they do not wear out, they work reliably and are resistant to heat, ionizing radiation and vibration. The direction of flow in pneumatic logic elements is switched with a turbulent free jet (control jet), which for example, emerges from a nozzle and entrains the fluid from the environment (boundary layer). Since the control jet is usually weaker than the jet to be deflected, we refer to the amplification effect.
This experimental unit – used in the aerodynamics trainer FM-1849-56 – allows the demonstration of the Coanda effect on a pneumatic logic element. The air flows through a Y-shaped channel with two outlets. The lateral inflow of air into the channel (control jet) can switch the air flow between the two outlets.
The contour of the channel is varied via pivoting and sliding elements, so as to study how the switchover works. Scales allow precise adjustment of the elements.
The experimental unit is attached to the FM-1849-56 trainer, simply and precisely with quick release fasteners.
Experiments
- Investigation of wall-guided air flow (coanda effect)
- Familiarization with the principle of pneumatic logic elements
- Study amplification effect in pneumatic elements
Specification
- Demonstration of the Coanda effect in pneumatic logic elements
- Accessories for FM-1849-56 aerodynamics trainer
- Transparent plate with vertical, horizontal and radial scales
- Y-channel with pivoting and sliding elements and vertical sliding wedge for adjusting different contours
- Adjustable contours for varying the air flow
