2D flapping wing by Michael Alletto - Revision history

Michael Alletto at 20:49, 31 January 2024

2024-01-31T20:49:38Z

Michael Alletto at 06:44, 17 January 2023

2023-01-17T06:44:55Z

Michael Alletto at 20:22, 7 January 2022

2022-01-07T20:22:54Z

Michael Alletto at 15:25, 3 August 2020

2020-08-03T15:25:27Z

Jozsef Nagy: /* 2D flapping wing */

2019-11-29T06:41:49Z

2D flapping wing

Jozsef Nagy at 06:38, 29 November 2019

2019-11-29T06:38:35Z

Jozsef Nagy: /* Results */

2019-11-29T06:35:59Z

Results

Jozsef Nagy at 06:35, 29 November 2019

2019-11-29T06:35:21Z

Jozsef Nagy at 06:32, 29 November 2019

2019-11-29T06:32:51Z

Jozsef Nagy at 06:32, 29 November 2019

2019-11-29T06:32:02Z

@@ Line 3: / Line 3: @@
 * '''affiliation''': WRD MS
 * '''contact''': <mail address='michael.alletto@gmx.de' description='author'>click here for email address</mail>
-* '''OpenFOAM versions''': v2212
+* '''OpenFOAM versions''': v2312
 * '''Published under''': CC BY-NC-ND license ([https://creativecommons.org/licenses creative commons licenses])

@@ Line 3: / Line 3: @@
 * '''affiliation''': WRD MS
 * '''contact''': <mail address='michael.alletto@gmx.de' description='author'>click here for email address</mail>
-* '''OpenFOAM versions''': v2112
+* '''OpenFOAM versions''': v2212
 * '''Published under''': CC BY-NC-ND license ([https://creativecommons.org/licenses creative commons licenses])

@@ Line 3: / Line 3: @@
 * '''affiliation''': WRD MS
 * '''contact''': <mail address='michael.alletto@gmx.de' description='author'>click here for email address</mail>
-* '''OpenFOAM versions''': v2006
+* '''OpenFOAM versions''': v2112
 * '''Published under''': CC BY-NC-ND license ([https://creativecommons.org/licenses creative commons licenses])

@@ Line 3: / Line 3: @@
 * '''affiliation''': WRD MS
 * '''contact''': <mail address='michael.alletto@gmx.de' description='author'>click here for email address</mail>
-* '''OpenFOAM versions''': v1906
+* '''OpenFOAM versions''': v2006
 * '''Published under''': CC BY-NC-ND license ([https://creativecommons.org/licenses creative commons licenses])
@@ Line 12: / Line 12: @@
 =[https://github.com/jnmlujnmlu/OpenFOAMTeaching/tree/master/MichaelAlletto 2D flapping wing]=
-You can download the case file [https://github.com/jnmlujnmlu/OpenFOAMTeaching/blob/master/MichaelAlletto/2dFlappingWing.tar.gz 2dFlappingWing.tar.gz] here.
+You can download the case file [https://gitlab.com/mAlletto/openfoamtutorials/-/tree/master/flappingWing] here.
 ==Introduction==

@@ Line 12: / Line 12: @@
 =[https://github.com/jnmlujnmlu/OpenFOAMTeaching/tree/master/MichaelAlletto 2D flapping wing]=
-You can download the case file [https://github.com/jnmlujnmlu/OpenFOAMTeaching/tree/master/MichaelAlletto sphereSplashSend.tar.gz] !!!!!!!!!!!!!!!! here.
+You can download the case file [https://github.com/jnmlujnmlu/OpenFOAMTeaching/blob/master/MichaelAlletto/2dFlappingWing.tar.gz 2dFlappingWing.tar.gz] here.
 ==Introduction==

@@ Line 66: / Line 66: @@
 [[File:ClCd_allettoflap.png|900px|center|left: temporal evolution of C<sub>d</sub> (blue) and C<sub>l</sub> (green); right: phase averaged C<sub>d</sub> and C<sub>l</sub>]]
-According to [3] the cycle of a flapping wing can be divided into five stages: the emergence of the leading edge vortex (LEV), the growth of the LEV, the lift--off of the LEV, the breakdown and decay of the LEV. For each of this stages the phase averaged scaled vorticity &omega; (left column of Figure !!!!!!!!!!!!!!!) and the pressure scaled by the mean flapping velocity squared and the density (right column of Figure !!!!!!!!!!!!!!!) is shown. The interpretation of the results and its comparison with the reference experiment is left to the interested reader.
+According to [3] the cycle of a flapping wing can be divided into five stages: the emergence of the leading edge vortex (LEV), the growth of the LEV, the lift--off of the LEV, the breakdown and decay of the LEV. For each of this stages the phase averaged scaled vorticity &omega; (left column of the figure below) and the pressure scaled by the mean flapping velocity squared and the density (right column of the figure below) is shown. The interpretation of the results and its comparison with the reference experiment is left to the interested reader.
 ==References==

@@ Line 62: / Line 62: @@
 ==Results==
-Figure !!!!!!!!!!!!!!!!!! shows the temporal evolution of the force coefficient (left) and the comparison of the phase averaged force coefficients with the experiments (right). Looking at the evolution of the force coefficient it is evident that the signal is not completely periodic as expected for this low Reynolds number. The interaction of the wing with the residual vorticities from the previous strokes seems to lead to a not completely periodic evolution of the forces on the wing. The agreement of the phase averaged coefficients with the experiments is satisfactory especially if we keep in mind that a 2D simulation is compared with a 3D experiment. In the simulation the influence of the flow from the root of the wing to the tip which is induced by a mean spanwise pressure gradient is completely disregarded. The peak of the force coefficients at the end of the cycle probably results from an too high influence of the wing rotation at the end of the cycle.
+The figure below shows the temporal evolution of the force coefficient (left) and the comparison of the phase averaged force coefficients with the experiments (right). Looking at the evolution of the force coefficient it is evident that the signal is not completely periodic as expected for this low Reynolds number. The interaction of the wing with the residual vorticities from the previous strokes seems to lead to a not completely periodic evolution of the forces on the wing. The agreement of the phase averaged coefficients with the experiments is satisfactory especially if we keep in mind that a 2D simulation is compared with a 3D experiment. In the simulation the influence of the flow from the root of the wing to the tip which is induced by a mean spanwise pressure gradient is completely disregarded. The peak of the force coefficients at the end of the cycle probably results from an too high influence of the wing rotation at the end of the cycle.
 [[File:ClCd_allettoflap.png|900px|center|left: temporal evolution of C<sub>d</sub> (blue) and C<sub>l</sub> (green); right: phase averaged C<sub>d</sub> and C<sub>l</sub>]]
 According to [3] the cycle of a flapping wing can be divided into five stages: the emergence of the leading edge vortex (LEV), the growth of the LEV, the lift--off of the LEV, the breakdown and decay of the LEV. For each of this stages the phase averaged scaled vorticity &omega; (left column of Figure !!!!!!!!!!!!!!!) and the pressure scaled by the mean flapping velocity squared and the density (right column of Figure !!!!!!!!!!!!!!!) is shown. The interpretation of the results and its comparison with the reference experiment is left to the interested reader.
 ==References==

← Older revision		Revision as of 06:35, 29 November 2019
Line 63:		Line 63:

	Figure !!!!!!!!!!!!!!!!!! shows the temporal evolution of the force coefficient (left) and the comparison of the phase averaged force coefficients with the experiments (right). Looking at the evolution of the force coefficient it is evident that the signal is not completely periodic as expected for this low Reynolds number. The interaction of the wing with the residual vorticities from the previous strokes seems to lead to a not completely periodic evolution of the forces on the wing. The agreement of the phase averaged coefficients with the experiments is satisfactory especially if we keep in mind that a 2D simulation is compared with a 3D experiment. In the simulation the influence of the flow from the root of the wing to the tip which is induced by a mean spanwise pressure gradient is completely disregarded. The peak of the force coefficients at the end of the cycle probably results from an too high influence of the wing rotation at the end of the cycle.		Figure !!!!!!!!!!!!!!!!!! shows the temporal evolution of the force coefficient (left) and the comparison of the phase averaged force coefficients with the experiments (right). Looking at the evolution of the force coefficient it is evident that the signal is not completely periodic as expected for this low Reynolds number. The interaction of the wing with the residual vorticities from the previous strokes seems to lead to a not completely periodic evolution of the forces on the wing. The agreement of the phase averaged coefficients with the experiments is satisfactory especially if we keep in mind that a 2D simulation is compared with a 3D experiment. In the simulation the influence of the flow from the root of the wing to the tip which is induced by a mean spanwise pressure gradient is completely disregarded. The peak of the force coefficients at the end of the cycle probably results from an too high influence of the wing rotation at the end of the cycle.
		+
		+	[[File:ClCd_allettoflap.png\|900px\|center\|left: temporal evolution of C<sub>d</sub> (blue) and C<sub>l</sub> (green); right: phase averaged C<sub>d</sub> and C<sub>l</sub>]]

	According to [3] the cycle of a flapping wing can be divided into five stages: the emergence of the leading edge vortex (LEV), the growth of the LEV, the lift--off of the LEV, the breakdown and decay of the LEV. For each of this stages the phase averaged scaled vorticity ω (left column of Figure !!!!!!!!!!!!!!!) and the pressure scaled by the mean flapping velocity squared and the density (right column of Figure !!!!!!!!!!!!!!!) is shown. The interpretation of the results and its comparison with the reference experiment is left to the interested reader.		According to [3] the cycle of a flapping wing can be divided into five stages: the emergence of the leading edge vortex (LEV), the growth of the LEV, the lift--off of the LEV, the breakdown and decay of the LEV. For each of this stages the phase averaged scaled vorticity ω (left column of Figure !!!!!!!!!!!!!!!) and the pressure scaled by the mean flapping velocity squared and the density (right column of Figure !!!!!!!!!!!!!!!) is shown. The interpretation of the results and its comparison with the reference experiment is left to the interested reader.

@@ Line 32: / Line 32: @@
 As for the other tutorials presented, the different zones (background mesh and the moving meshes) should be differentiated by the scalar field zoneID. This field should have a different number (starting with zero) for each mesh (see figure below). The overset method implemented in OpenFOAM detects itself the different cell types. The cells adjacent to the patch denominated as overset are chosen as interpolated. For this cells the matrix coefficients are not derived from the finite volume discretization but using one of overset interpolation method chosen by the user. The cells which are inside the wing are flagged as hole cells and exclude from the calculation. The other cells are treated as calculated (the matrix coefficients are derived from a finite volume discretization). The cell types are visualized on the right of the figure below.
-[[File:ZoneIDflap.png|400px|center|zoneID and cell types (blue calculated, gray interpolated and red hole cells)]]
+[[File:ZoneIDflap.png|900px|center|zoneID and cell types (blue calculated, gray interpolated and red hole cells)]]
 The kinematics of the wing are imposed by choosing the adequat motion solver. Since the wing executes a sinusoidal movement in x-direction and pitches at the and of the half stroke with a linear change of the angle &beta; (see figure below on wing kinematics where the evolution of the x-position of and the angle &beta; during the first cycle is shown), the tabulated6DoFMotion function is chosen. This function allows to impose the temporal evolution of the displacement in x-,y- and z-direction and also the rotation about the same axis. The displacements and rotation are relative to the initial position.
@@ Line 52: / Line 52: @@
   </TT>
-[[File:Kinematics_alettoflap.png|900px|center|kinematics of the wing]]
+[[File:Kinematics_alettoflap.png|400px|center|kinematics of the wing]]
 ===Case specific postprocessing===