SimScale simulation projects by Retsam | Page 1

Retsam's profile

That kind of profile is preferred for HVAT (instead of NACA0018). Let's see how it behaves

Using NACA 0020 profile slated Vertical Wind Turbin study

Small mesh and study of efficiency

Minimal mesh and just two simulations to evaluate forces on a small propeller related to advance speed.

TET mesh testing on E423 high lift profile

Tutorial project for a flow analysis of a pipe junction. The project only provides the geometry to start with. See our tutorials section to have a look at the step-by-step instructions to set up the simulation.

TET mesh testing on NACA0012 profile evaluation of domain size impact

Simulating air torus throwing with very short pressure impulse from inside a box

Tutorial project to set up the Hex-dominant Parametric mesh for rotating geometries. This mesh can then be used for MRF and AMI simulations that incorporate rotation effects.

Project does contain examples of SimScale problems with features / simulations

Define minimum SimScale resources to study a 'twister' (vortex) and analyse its behavior in Incompressible CFD simulations

Using Coanda effect is not a standard in drone design. I will evaluate its capacity on a model with minimum elements count (should be about 3).
However I have also a 'hidden agenda' linked to that study. This is related to ring shaped forms, created by rotating medium (this can be air or water dynamic structures). They resemble 'smoke rings', moving through the air with great stability. What is even more surprising is the fact, that air rings can be formed under water and dolphins do it and play with it for a long while (possibly few millions years).
When observing air rings created with simple boxes with a hole, one can notice the great velocity of generated ring, getting progressively bigger due to Magnus effect. Rotating energy of the ring is preserved for a long time and is not lost in a wake. If it would be the case, ring would stop advancing after few centimetres. 
In order to simulate that result to at least a small extend, I need to use Coanda effect, allowing flow to follow the curve of the body. Body will be a ring shaped object, tested with external 'momentum source'. Momentum source is a simplification of 'propeller' , which directs flow against expected vector of displacement. Momentum source is present in a hole of the ring. Few tests concerning its size and way of redirecting the flow will be simulated.

Rotating cylinder in a fluid creates lift, known as 'Magnus effect' which is proportional to stream speed and surface rotational speed of cylinder. I thought that it is a forgotten technology, remembering just experiments of Captain Cousteau with 'turbosail' in eighties. Then I discovered a modern ship construction with 'Sail-Rotors'. She is a German 'E-Ship 1' commercial cargo, equipped with four rotors of 4 meters of diameters. In 2013 Enercon company, the owner of the ship, published official document about performance of those rotating masts after navigating more than 150 000 miles.

The capabilities of rotating cylinders to produce lift were studied first at Langley NACA Laboratory. Mr Raid found that in appropriate conditions rotor can develop very high values of lift to drag ratio.

Such a simple form of propulsion system allows to test SimScale CFD tools quite easily and also to understand how lift / drag ratio relates to wind speed / rotation speed, as that relation is not linear. 

In my setup I created much smaller geometry: rotor diameter is 0.3 m and high 2.0 m. Sharp edges of cylinder were removed in order to avoid meshing overhead. Rotation is along Z axe, rotor position  starts at Z equal 0 and extends to 2 m.

Wind speed is setup to 10 m/s and rotor surface or peripheral speed to similar speed, about 50 rad/s. As rotating cylinder creates asymmetric air flow, walls instead of 'no-slip' were set to 'Custom' P and V  to 'Zero gradient', k and omega to 'Fixed values' appropriate to air. Basically those walls are 'transparent' and will not impact on rotating body.

I decided also to provide progressive rotation speed to rotor: on 120 seconds of simulation, rotor accelerates to final 50 rad/s for 50 seconds, using inversely parabolic slope. This allows to avoid a strong wake from body starting to rotate: That approach helps to maintain laminar flow and shorten the simulation time.

UNV format TET mesh import and CFD internal simulation of house ventilation.

Experimenting with aerodynami aspect of Truck shape

That seemingly interesting ceiling fan shape project was found in InShape public repository. I would like to compare it to standard triple blades ceiling fan which was simulated on Fluent 15 and reality checked by students in Sri Lanka. However that study is far from a good reference, hence I had to find a simple similar three-blades geometry and measure fan effects while using the same rotation speed.

There an odd effect of half pipe wing drag / lift related to flow speed. https://www.sciencemag.org/news/2016/11/how-fly-pipe. This can be used as a mechanical switch.

Simulating air torus throwing with very short pressure impulse from inside the box.

All kind of wings exist already in nature, simplified to extreme by evolution. In aerospace engineers are mimicking the nature and adding features for conditions which does not exit in animal realm.

I would like to study the 'essence' of a wing, which does not exist in nature and is not used by engineers.

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