The Cyclifter: a monoshaft cycloidal rotor aircraft animated with FreeCADs Assembly4 workbench louisgag 2024-02-09 | The granted patent: https://register.dpma.de/DPMAregister/pat/PatSchrifteneinsicht?docId=DE102022114599B4The FreeCAD files: forum.freecad.org/viewtopic.php?t=85139The main goal and difference between this aircraft and other cyclogyros is that it has a single drive shaft and still allows high agility.The dream behind this device would be to make a human powered VTOL implementation of it, as you can see in the related patent (number DE102022114599). This German patent is also available for licensing opportunities or acquisition.The rotor has 4 blades, a radius of 84.25 mm and is designed to rotate at up to 5300 rpm. A prototype rotor with the same design has been built and tested and is presented in the paper "Aerodynamic Performance of a Hovering Cycloidal Rotor: A CFD Study with Experimental Validation," which will be soon published by the Journal of the American Helicopter Society.This aircraft was designed and tested for the project "A Novel and Simple Aircraft Requiring Minimal Power to Hover" funded by the Alexander von Humboldt Foundation Research Fellowships for Postdoctoral Researchers and conducted at the Institute of Aerodynamics and Gas Dynamics at the University of Stuttgart. This project would have never been possible without the support of many colleagues at the institute. More info: http://louisgagnon.com/research/AvH_cyclo.htmlThe 3D model and animation were done in FreeCAD with its Assembly4 and Render workbenches, using many tricks and Python to make things run smoothly.
Wake of a Cycloidal Rotor Solved Using DDES CFD with 284 Million Cells louisgag 2023-04-20 | This video shows the vortices identified by the Lamda2 criterion for a 284 million cell cyclorotor CFD simulation run to test the limits of OpenFOAM's HPC scalability when working with multiple and embedded rotating meshes.To facilitate code improvement by developers and the community, a repository (doi.org/10.18419/darus-3340) provides all the necessary files to either reconstruct the case or run it as is.The rotor has 4 blades, a radius of 84.25 mm and rotates at 1695 RPM. The maximum pitch angles of the upper and lower paths are 35° and 38°, respectively, and they occur at positions 100° and 277°.The case was run using OpenFOAM (pimpleFoam) on the HLRS-Hawk supercomputer.A more detailed description of the case is available in the (currently preprint) paper "Parametric Aerodynamic Study of a 3D Printed Cycloidal Rotor Prototype Designed for the Best Figure of Merit" which was submitted to the Journal of the American Helicopter Society: researchgate.net/publication/369473318_Parametric_Aerodynamic_Study_of_a_3D_Printed_Cycloidal_Rotor_Prototype_Designed_for_the_Best_Figure_of_MeritProject Info: “A Novel and Simple Aircraft Requiring Minimal Power to Hover” project funded by the Alexander von Humboldt Foundation Research Fellowships for Postdoctoral Researchers: http://louisgagnon.com/research/AvH_cyclo.html and conducted at the Institute of Aerodynamics and Gas Dynamics
Surface Pressure of a Cycloidal Rotor Solved Using DDES CFD with 284 Million Cells louisgag 2023-04-20 | This video shows the blade surface pressure along with the dimmed vorticity identified by the Lambda2 criterion for a 284 million cell cyclorotor CFD simulation run to test the limits of OpenFOAM's HPC scalability when working with multiple and embedded rotating meshes.To facilitate code improvement by developers and the community, a repository (doi.org/10.18419/darus-3340) provides all the necessary files to either reconstruct the case or run it as is.The rotor has 4 blades, a radius of 84.25 mm and rotates at 1695 RPM. The maximum pitch angles of the upper and lower paths are 35° and 38°, respectively, and they occur at positions 100° and 277°.The case was run using OpenFOAM (pimpleFoam) on the HLRS-Hawk supercomputer.A more detailed description of the case is available in the (currently preprint) paper "Parametric Aerodynamic Study of a 3D Printed Cycloidal Rotor Prototype Designed for the Best Figure of Merit" which was submitted to the Journal of the American Helicopter Society: researchgate.net/publication/369473318_Parametric_Aerodynamic_Study_of_a_3D_Printed_Cycloidal_Rotor_Prototype_Designed_for_the_Best_Figure_of_MeritProject Info: “A Novel and Simple Aircraft Requiring Minimal Power to Hover” project funded by the Alexander von Humboldt Foundation Research Fellowships for Postdoctoral Researchers: http://louisgagnon.com/research/AvH_cyclo.html and conducted at the Institute of Aerodynamics and Gas Dynamics
Cyclorotors: How Much of a Change can a DDES Simulation Bring? louisgag 2022-08-24 | Conclusion: refined vortices, similar streamlines, slightly more chaotic pressure distribution on the blade.Tip: watch full screen with 1440p resolution (gear at bottom, quality menu) and loop (right-click menu).This video shows the streamlines (velocity lines rendered as LIC) and pressure distribution in the middle of the cycloidal rotor blade for both a URANS (above) and a DDES (below) case using the same mesh and timestep.Both cases are ran in 3D using OpenFOAM (pimpleFoam) on the HLRS-Hawk computers.The rotor has 4 blades, a radius of 84.25 mm and turns at 5300 RPM. The maximum pitch angles of the upper and lower paths are 35° and 38°, respectively, and they occur at position 100° and 277°, respectively.Typical dynamic stall behavior can be observed: blade pressure and suction sides switch between the upper and lower portions of the rotation and dynamic stall occurs and the end of the upper course.NOTE: This is an improved version of my "Pressure plot and LIC-Streamlines in the middle of a Cyclorotor blade" video.Project Info: “A Novel and Simple Aircraft Requiring Minimal Power to Hover” project funded through the Alexander von Humboldt Foundation Research Fellowships for Postdoctoral Researchers: http://louisgagnon.com/research/AvH_cyclo.html
Comparison of the flow field around a cycloidal rotor prototype and a URANS CFD simulation louisgag 2022-07-20 | The experimental flow field at 1695 RPM measured using a smoke generator and a propeller-based wind speed sensor is shown on the left side with the green streamlines and the spheres, which show the velocity magnitude from 0 (blue) to 10 m/s (red). The results of a 3D URANS CFD simulation conducted with OpenFOAM (pimpleFOAM) are shown using the same color scale on the right side.Rotor has a radius of 84.25 mm and 4 blades.The cycloidal rotor is represented by a cylinder having the radius and span length as the rotor.Project Info: “A Novel and Simple Aircraft Requiring Minimal Power to Hover” project funded through the Alexander von Humboldt Foundation Research Fellowships for Postdoctoral Researchers: http://louisgagnon.com/research/AvH_cyclo.html
Pressure plot and LIC-Streamlines in the middle of a Cyclorotor blade louisgag 2022-07-20 | Note: streamlines are better visible in full-screen mode.This video shows the streamlines and pressure distribution in the middle of the cyclorotor blade for both a URANS (above) and a DDES (below) case using the same mesh.Both cases are ran in 3D using OpenFOAM (pimpleFoam) on the HLRS-Hawk computers.The rotor has 4 blades, a radius of 84.25 mm, and turns at 5300 RPM.
Chimera (overset) interpolation cells on a modified openFoam version louisgag 2021-11-19 | The original OpenFOAM-v2012 code was modified to allow pushing the interpolation interface away from the component mesh and to also speed up the search for donor and acceptor cells.This animation show the interpolation interfaces of the background mesh (light yellow) and component blade mesh (here dark pink).More info on GitHub: github.com/louisgag/openFoam-Overset-SpeedUpThe mesh shown is for the overset twin version of this AMI-case: youtube.com/watch?v=q0pafX63_x0Project Info: “A Novel and Simple Aircraft Requiring Minimal Power to Hover” project funded through the Alexander von Humboldt Foundation Research Fellowships for Postdoctoral Researchers: http://louisgagnon.com/research/AvH_cyclo.html
Oscillating Airfoil DDES with OpenFOAM louisgag 2021-11-04 | Reproducing the airfoil motion of Lee, T., and Gerontakos, P. (2004).The rendering shows the lambda2 isosurfaces colored by distance.The simulation is described in an upcoming paper named "Investigation of the Reynolds Number on the Performance of a Cycloidal Rotor" as: "a NACA 0012 airfoil with a chord length of c = 0.15 m [with] an initial angle of attack m (AoA) of 10° and [...] oscillating with an angular velocity of Ω = 46.6667 rad/s. The free stream velocity is U∞ = 35 m/s with a turbulence intensity of Tu = 0.08%. The kinematic viscosity is ν = 38.889 · 10−6 m^2/s ."Accompanying paper: doi.org/10.1115/1.4056844 and bachelor thesis: https://stg.ibs-bw.de/aDISWeb/app?service=direct/0/Home/$DirectLink&sp=SOPAC02&sp=SAKSWB-IdNr1763925978Project Info: “A Novel and Simple Aircraft Requiring Minimal Power to Hover” project funded through the Alexander von Humboldt Foundation Research Fellowships for Postdoctoral Researchers: http://louisgagnon.com/research/AvH_cyclo.html
Dynamically Morphing Blades on a Cycloidal Rotor louisgag 2021-09-03 | Vorticity fields comparison of baseline rotor (0%) to that with dynamically morphing blades for NACA camber morphing 0:00; Leading Edge (LE) morphing 0:36; Trailing Edge (TE) morphing 1:13This videos accompanied the presentation of the master thesis research done by Ms. Doudou Huang at IAG on the effect of dynamically morphing blades on the efficiency of a cycloidal rotor. Presentation: http://louisgagnon.com/articlesScientifiques/HuangGagnon2021_EASN_morphingCyclorotor.pdfProject Info: “A Novel and Simple Aircraft Requiring Minimal Power to Hover” project funded through the Alexander von Humboldt Foundation Research Fellowships for Postdoctoral Researchers: http://louisgagnon.com/research/AvH_cyclo.html
Cycloidal Rotor with Optimized Spline-Based Pitch-Control Function louisgag 2021-08-04 | This video shows a 2D URANS CFD simulation of a cyclorotor having a pitch function optimized using the genetic algorithm on a Double-multiple streamtube inflow model and Blade-Element Theory.The CFD model is a small progression based on the original work by Shawn Cogan: https://stg.ibs-bw.de/aDISWeb/app?service=direct/0/Home/$DirectLink&sp=SOPAC02&sp=SAKSWB-IdNr1742829899 which was presented at the 10th EASN Conference (https://easnconference.eu/sites/default/files/10th_EASN_Virtual_Conference-Prefinal_Agenda.pdf) and the video will be shown during the 11th EASN Conference: https://easnconference.eu/sites/default/files/11th_EASN_Virtual_Conference-Preliminary_Agenda_4.pdfProject Info: “A Novel and Simple Aircraft Requiring Minimal Power to Hover” project funded through the Alexander von Humboldt Foundation Research Fellowships for Postdoctoral Researchers: http://louisgagnon.com/research/AvH_cyclo.html
Cycloidal Rotor: 3D URANS CFD of a 3-Blade Barebone Rotor louisgag 2021-07-30 | The video shows a hovering three-dimensional barebone cyclorotor computational fluid dynamics simulation after 14 rotor revolutions.Original blog entry: http://louisgagnon.com/scBlog/rotor3DCFD.htmlWhat is shown:00:08 - Relative atmospheric pressure on the blades, the effects of the major dynamic stall event are mostly seen shortly after 270°. Most of the thrust is generated by pressure and one can see that the bottom passage has the strongest contribution.00:45 - The coefficient of friction on the blade, considering that the blade rotates and oscillates, identifies in yellow positions where the relative velocity between blade and fluid goes to zero and indicates likelihood for detached flow. Once again, the position shortly after 270° shows the strongest action, because of dynamic stall.01:08 - The velocity LIC lines in the rotating rotor reference frame (rotating but not locally oscillating) on the first layer of cells above the blade give another, more global, view of the dynamic stall action and the vortices that are created by the blade.01:33 - The lambda2 contour surfaces show these vortices, such has the horseshoe vortex which detaches from the blade around angle 360° and the tip vortices of the blades. The lambda2 surfaces in the first 1 cm above the blade are cut out from the rendering to allow better visualization of the blade's coefficient of friction.02:04 - The same lambda2 surfaces are now colored by the vorticity projected on the non-oscillating orbital blade path to highlight the direction of the vortices, in particular the tip vortices which have a different direction of rotation on the top passage as in the bottom one, because of the combination direction of motion of the blade and the thrust it generates.02:36 - The sensitivity of the lambda2 surfaces is extended to identify the large turbulent structures that leave the upper blades and travel through the rotor. The pressure bubbles shown on the rearwards half the blades correlate with the magnitude of the generated thrust and also indicate that the large eddies coming from the upper blade have little influence on the lower passage. The LIC lines indicate the path of the flow inside the vortices identified by the lambda2 surfaces and the color indicates the radial distance from the center of the rotor, to ease understanding of motion of the turbulent structures traveling through the rotor.03:16 - The arrows now allow identifying the inflow and wake generated by the rotor. Their size is scaled according to the square root of the velocity vector magnitude and they are shown for any velocity magnitude above 5 cm/s, thus allowing to identifying the zone of influence of the rotor. Although the arrows are filtered out near the blades, some local irregularities are seen and correspond to the flow response to the passage of a blade. Because of the small aspect ratio and the absence of endplates or side disks, the inflow is highly three-dimensional and the flow leaving the rotor forms, contrary to what is usually seen in 2D simulations, a rather wide wake. The arrows also highlight the acceleration of the flow through the rotor and also the marked difference of velocity between the upper and lower passages of the blades.04:10 - The side view of the wake further pictures that air flows into the rotor from all sides and also in the middle of the rotor, thus between the two blade passages, while the wake remains rather bidimensional. As expected the flow is also curved through the rotor, thus bending the wake towards the positive x-direction.Geometry: Blade chord is 15 cm and aspect ratio is 2; rotor radius is 50 cm. The motion function is given at the beginning of the video.CFD model: Turbulence is implemented using the unsteady Reynolds-averaged Navier-Stokes method with a k-ω SST turbulence model with a fully resolved wall using a first grid cell thickness of 6.6 μm. The v2012 pimpleFoam solver is used and the grid has pill-shaped moving mesh zones which contain the blades and which are coupled to a rotating background mesh through the AMI interface method. No symmetry is used and the complete mesh has 20.5 million cells. Second order schemes in both time and space are used.Computational aspects: The simulation was run on the Hawk supercomputer of the High Performance Computing Center Stuttgart (HLRS) using 2048 processes on 32 nodes, taking approximately 6 seconds per timestep, each covering 0.5 degrees of rotation, thus leading to a maximum Courant number varying between 160 and 200.Acknowledgments: This simulation was conducted at the Institute of Aerodynamics and Gas Dynamics of the University of Stuttgart for the "A Novel and Simple Aircraft Requiring Minimal Power to Hover" and is financed by the Humboldt Research Fellowship for postdoctoral researchers. Free open-source software used: FreeCAD and naca4gen and GNU Octave for the blade profile, OpenFOAM for the simulation, and ParaView and Python for post-processing.
Cycloidal Rotor Traditional Pitch Control Mechanism Animation - Updated Version louisgag 2021-07-30 | Observe the motion of the blue point which sets the position of the pitch control rods. It imposes the synchronous harmonic pitching of the individual blades which produce thrust in the direction contrary to the offset of the blue point with respect to the fixed central axes (the black cross).Made with FreeCAD's sketcher panel
Start Vortex and Wake of a Cycloidal rotor CFD Simulation louisgag 2021-01-20 | This video presents the results of a computational fluid dynamics simulation that was run for a cycloidal rotor in hover. Reynolds and Mach numbers are approximately Re=90k and Ma=0.03, respectively. The local blade oscillation's reduced frequency is κ=0.15 and it pitches with a sinusoidal function varying between 19° and 31° at top- and bottom-most positions, respectively. More details in the following paper: link.springer.com/chapter/10.1007/978-3-030-79561-0_33Project Info: “A Novel and Simple Aircraft Requiring Minimal Power to Hover” project funded through the Alexander von Humboldt Foundation Research Fellowships for Postdoctoral Researchers: http://louisgagnon.com/research/AvH_cyclo.html
Aerodynamic Fairings on a Cycloidal Rotor louisgag 2020-11-13 | This video presents the results of a series of computational fluid dynamics simulations that were run for a cycloidal rotor in hover. The objective was to see if aerodynamic fairings could improve the efficiency of such rotors. Reynolds and Mach numbers are approximately Re=90k and Ma=0.03, respectively. The local blade oscillation's reduced frequency is κ=0.15 and it pitches with a sinusoidal function varying between 19° and 31° at top- and bottom-most positions, respectively. The most notable impacts are the appearance of a new regime for the cases with large asymmetric fairings which results in a displacement of the maximal thrust and power on the rotor path and in the rotation of the global thrust vector. More details in the following paper: link.springer.com/chapter/10.1007/978-3-030-79561-0_33
OpenFOAM-AMI Oscillating Airfoil with Dynamic Stall louisgag 2020-10-09 | This simulation reproduces the pitching airfoil case of LEE, T., & GERONTAKOS, P. (2004). Investigation of flow over an oscillating airfoil. Journal of Fluid Mechanics, 512, 313-341. doi:10.1017/S0022112004009851Project Info: “A Novel and Simple Aircraft Requiring Minimal Power to Hover” project funded through the Alexander von Humboldt Foundation Research Fellowships for Postdoctoral Researchers: http://louisgagnon.com/research/AvH_cyclo.html
Example 2D Cycloidal Rotor Animation with Surface LIC Rendering from Paraview louisgag 2020-07-10 | This video showcases the use of the surface LIC rendering from Paraview and vorticity fields of a 2D CFD simulation of an 8-blade cycloidal rotor. Note that the starting vortices are not yet gone.Project Info: “A Novel and Simple Aircraft Requiring Minimal Power to Hover” project funded through the Alexander von Humboldt Foundation Research Fellowships for Postdoctoral Researchers: http://louisgagnon.com/research/AvH_cyclo.html
Cycloidal Rotor Traditional Pitch Control Mechanism Animation louisgag 2019-09-27 | Made with FreeCAD's sketcher panel
Cyclogyro multibody dynamics concept study louisgag 2018-09-10 | Cycloidal rotor aircraft and helicopter concept studies of untethered flight simulations created with the MBDyn multibody dynamics toolbox.This is a companion video for the following article: Gagnon, L., Masarati, P., « Autonomous Untethered Flight of Multibody Dynamics Rotorcraft With Cycloidal Rotors », DETC2018-85152, ASME IDETC/CIE 2018, Québec City, Canada, August 26-29, 2018
Multibody Dynamics Helicopter in Free Flight v2 louisgag 2017-06-20 | Red helicopter is imposed path to be followed live by the other one. Improved optimization of the automatic control system used for youtu.be/FzZDJDsBSfE to reduce cabin/control vibrations.Perfect static position match is still not attained, possibly due to the combination of objectives between energy use, cabin stability, and path following capacity. Other possibilities: integrator part of the PID, or SAS parameters. Model optimized using a different path than the one displayed here. Each bar represents one meter.
Multibody Dynamics Heligyro Compound Helicopter in Free Flight louisgag 2017-06-14 | Rigid Heligyro model made with MBDyn (MBDyn.org) using a PID controller with SAS and filters in progress of being fully tuned. Aerodynamics of the main rotor are modeled with blade lift, drag, and moment tables while the rear rotor is modeled as a force. In this video representing 30s of real time. This video displays initial acrobatics prior to obtaining the final control system parameters from optimization. Rendered with Blendyn: http://github.com/zanoni-mbdyn/blendyn/wikiMore info on the research project: http://louisgagnon.com and http://www.researchgate.net/publication/310625903_Flight_scenarios_study_of_two_cycloidal_rotor_aircraft_concepts
Multibody Dynamics Helicopter in Free Flight louisgag 2017-03-31 | Rigid helicopter model made with MBDyn (MBDyn.org) using a PID controller with SAS and filters tuned using hover flight only. Aerodynamics of the main rotor are modeled with blade lift, drag, and moment tables while the rear rotor is modeled as a force. In this video representing 180s of real time, it follows a path consisting of hover, very large forward acceleration and displacement, lateral quick and small displacements, backward translation, and upwards displacement. Rendered with Blendyn: http://github.com/zanoni-mbdyn/blendyn/wikiMore info on the research project: http://louisgagnon.com and http://www.researchgate.net/publication/310625903_Flight_scenarios_study_of_two_cycloidal_rotor_aircraft_concepts
Heligyro path following multibody simulation louisgag 2017-01-27 | This multibody simulation used a very coarse control algorithm to test the capability of the Heligyro concept against the traditional Helicopter to follow a given trajectory. The objective was to hover on the green sphere. The simulation is done using MBDyn (http://www.mbdyn.com) and the rendering is done using Blendyn (http://github.com/zanoni-mbdyn/blendyn/). More info on the simulations is given in the following article: http://www.researchgate.net/publication/310625903_Flight_scenarios_study_of_two_cycloidal_rotor_aircraft_concepts
Quadricyclogyro path following multibody simulation louisgag 2017-01-27 | This multibody simulation used a very coarse control algorithm to test the capability of the Quadricyclogyro aircraft concept to follow a given trajectory. The simulation is done using MBDyn (http://www.mbdyn.com) and the rendering is done using Blendyn (http://github.com/zanoni-mbdyn/blendyn/). More info on the simulations is given in the following article: http://www.researchgate.net/publication/310625903_Flight_scenarios_study_of_two_cycloidal_rotor_aircraft_concepts
Blender and MBDyn semi-trailer example, front-view louisgag 2015-02-17 | Semitrailer truck simulation ran with MBDyn and rendered with Blender. This is a test run, don't consider the multibody dynamics results as valid. Project details on http://louisgagnon.com
Blender and MBDyn semi-trailer example louisgag 2015-02-17 | Semitrailer truck simulation ran with MBDyn and rendered with Blender. This is a test run, don't consider the multibody dynamics results as valid. Project details on http://louisgagnon.com
Heligyro louisgag 2014-11-06 | Concept helicopter rendered with a MBDyn multibody aeroelastic simulation of a cycloidal rotor. More project details on http://louisgagnon.com and http://www.crop-project.eu/
McGill Electric Snowmobile Towing a Snowboarder louisgag 2007-09-19 | Too fast for the snowboard! ;-)
McGill Electric Snowmobile Towing a Snowboarder louisgag 2007-09-19 | This is Albert Matthews the pro-boarder! ;-)
McGill Electric Snowmobile Description Technique louisgag 2007-09-19 | Vue sous le capot de la motoneige électrique. Under the hood of the electric snowmobile.
McGill Electric Snowmobile louisgag 2007-09-19 | The snowmobile is towed after successfully completing the 10 miles endurance run. Yeah, we need to deal with that energy problem!
Electric Snowmobile Fun louisgag 2007-04-02 | Some testing of our new prototype. Its 100% electric!! checkout http://www.electricsnowmobile.mcgill.ca for more!
McGill Electric Snowmobile louisgag 2007-01-28 | Some testing of our new prototype. Its 100% electric!! checkout http://www.electricsnowmobile.mcgill.ca for more!
McGill Electric Snowmobile louisgag 2007-01-28 | Some testing of our old prototype (the new one is much faster). Its 100% electric!! checkout http://www.electricsnowmobile.mcgill.ca for more!
