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Prof. Christophe Volat
Laboratory of Modelling and Diagnostic of Electrical Power Network Equipment (MODELE), Université du Québec à Chicoutimi, 555 Boulevard de l’Université, Chicoutimi, QC G7H 2B1, Canada

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0 Electrical Engineering
0 Numerical Simulation
0 Power Engineering
0 Power Transmission
0 Finite element method

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Finite element method

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Journal article
Published: 02 April 2021 in Aerospace
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In order to study ice protection systems for rotating blades, a new experimental setup has been developed at the Anti-Icing Materials International Laboratory (AMIL). This system consists of two small-scale rotating blades in a refrigerated icing wind tunnel where atmospheric icing can be simulated. Power is brought to the blades through a slip ring, through which the signals of the different sensors that are installed on the blades also pass. As demonstrated by the literature review, this new setup will address the need of small-scale wind tunnel testing on electrically powered rotating blades. To test the newly designed apparatus, preliminary experimentation is done on a hybrid ice protection system. Electrothermal protection is combined with different surface coatings to measure the impact of those coatings on the power consumption of the system. In anti-icing mode, the coatings tested did not reduce the power consumption on the system required to prevent ice from accumulating on the leading edge. The coatings however, due to their hydrophobic/superhydrophobic nature, reduced the power required to prevent runback ice accumulation when the leading edge was protected. One of the coatings did not allow any runback accumulation, limiting the power to protect the whole blades to the power required to protect solely the leading edge, resulting in a potential 40% power reduction for the power consumption of the system. In de-icing mode, the results with all the substrates tested showed similar power to achieve ice shedding from the blade. Since the coatings tested have a low icephobicity, it would be interesting to perform additional testing with icephobic coatings. Also, a small unheated zone at the root of the blade prevented complete ice shedding from the blade. A small part of the ice layer was left on the blade after testing, meaning that a cohesive break had to occur within the ice layer, and therefore impacting the results. Improvements to the setup will be done to remedy the situation. Those preliminary testing performed with the newly developed test setup have demonstrated the potential of this new device which will now allow, among other things, to measure heat transfer, force magnitudes, ice nucleation, and thermal equilibrium during ice accretion, with different innovative thermal protection systems (conductive coating, carbon nanotubes, impulse, etc.) as well as mechanical systems. The next step, following the improvements, is to measure forced convection on a thermal ice protection system with and without precipitation and to test mechanical ice protection systems.

ACS Style

Eric Villeneuve; Caroline Blackburn; Christophe Volat. Design and Development of an Experimental Setup of Electrically Powered Spinning Rotor Blades in Icing Wind Tunnel and Preliminary Testing with Surface Coatings as Hybrid Protection Solution. Aerospace 2021, 8, 98 .

AMA Style

Eric Villeneuve, Caroline Blackburn, Christophe Volat. Design and Development of an Experimental Setup of Electrically Powered Spinning Rotor Blades in Icing Wind Tunnel and Preliminary Testing with Surface Coatings as Hybrid Protection Solution. Aerospace. 2021; 8 (4):98.

Chicago/Turabian Style

Eric Villeneuve; Caroline Blackburn; Christophe Volat. 2021. "Design and Development of an Experimental Setup of Electrically Powered Spinning Rotor Blades in Icing Wind Tunnel and Preliminary Testing with Surface Coatings as Hybrid Protection Solution." Aerospace 8, no. 4: 98.

Journal article
Published: 22 May 2020 in Aerospace
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The objective of this research project is divided in four parts: (1) to design a piezoelectric actuator-based de-icing system integrated to a flat plate experimental setup and develop a numerical model of the system with experimental validation, (2) use the experimental setup to investigate actuator activation with frequency sweeps and transient vibration analysis, (3) add ice layer to the numerical model and predict numerically stresses for different ice breaking with experimental validation, and (4) bring the concept to a blade structure for wind tunnel testing. This paper presents the first objective of this study. First, preliminary numerical analysis was performed to gain basic guidelines for the integration of piezoelectric actuators in a simple flat plate experimental setup for vibration-based de-icing investigation. The results of these simulations allowed to optimize the positioning of the actuators on the structure and the optimal phasing of the actuators for mode activation. A numerical model of the final setup was elaborated with the piezoelectric actuators optimally positioned on the plate and meshed with piezoelectric elements. A frequency analysis was performed to predict resonant frequencies and mode shapes, and multiple direct steady-state dynamic analyses were performed to predict displacements of the flat plate when excited with the actuators. In those steady-state dynamic analysis, electrical boundary conditions were applied to the actuators to excite the vibration of the plate. The setup was fabricated faithful to the numerical model at the laboratory with piezoelectric actuator patches bonded to a steel flat plate and large solid blocks used to mimic perfect clamped boundary condition. The experimental setup was brought at the National Research Council Canada (NRC) for testing with a laser vibrometer to validate the numerical results. The experimental results validated the model when the plate is optimally excited with an average of error of 20% and a maximal error obtained of 43%. However, when the plate was not efficiently excited for a mode, the prediction of the numerical data was less accurate. This was not a concern since the numerical model was developed to design and predict optimal excitation of structures for de-icing purpose. This study allowed to develop a numerical model of a simple flat plate and understand optimal phasing of the actuators. The experimental setup designed is used in the next phase of the project to study transient vibration and frequency sweeps. The numerical model is used in the third phase of the project by adding ice layers for investigation of vibration-based de-icing, with the final objective of developing and integrating a piezoelectric actuator de-icing system to a rotorcraft blade structure.

ACS Style

Eric Villeneuve; Christophe Volat; Sebastian Ghinet. Numerical and Experimental Investigation of the Design of a Piezoelectric De-Icing System for Small Rotorcraft Part 1/3: Development of a Flat Plate Numerical Model with Experimental Validation. Aerospace 2020, 7, 62 .

AMA Style

Eric Villeneuve, Christophe Volat, Sebastian Ghinet. Numerical and Experimental Investigation of the Design of a Piezoelectric De-Icing System for Small Rotorcraft Part 1/3: Development of a Flat Plate Numerical Model with Experimental Validation. Aerospace. 2020; 7 (5):62.

Chicago/Turabian Style

Eric Villeneuve; Christophe Volat; Sebastian Ghinet. 2020. "Numerical and Experimental Investigation of the Design of a Piezoelectric De-Icing System for Small Rotorcraft Part 1/3: Development of a Flat Plate Numerical Model with Experimental Validation." Aerospace 7, no. 5: 62.

Journal article
Published: 02 May 2020 in Aerospace
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The objective of this research project is divided in four parts: (1) to design a piezoelectric actuator-based de-icing system integrated to a flat plate experimental setup and develop a numerical model of the system with experimental validation, (2) use the experimental setup to investigate actuator activation with frequency sweeps and transient vibration analysis, (3) add an ice layer to the numerical model and predict numerically stresses at ice breaking with experimental validation, and (4) bring the concept to a blade structure for wind tunnel testing. This paper presents the third part of the investigation in which an ice layer is added to the numerical model. Five accelerometers are installed on the flat plate to measure acceleration. Validation of the vibration amplitude predicted by the model is performed experimentally and the stresses calculated by the numerical model at cracking and delamination of the ice layer are determined. A stress limit criteria is then defined from those values for both normal stress at cracking and shear stress at delamination. As a proof of concept, the numerical model is then used to find resonant modes susceptible to generating cracking or delamination of the ice layer within the voltage limit of the piezoelectric actuators. The model also predicts a voltage range within which the ice breaking occurs. The experimental setup is used to validate positively the prediction of the numerical model.

ACS Style

Eric Villeneuve; Christophe Volat; Sebastian Ghinet. Numerical and Experimental Investigation of the Design of a Piezoelectric De-Icing System for Small Rotorcraft Part 3/3: Numerical Model and Experimental Validation of Vibration-Based De-Icing of a Flat Plate Structure. Aerospace 2020, 7, 54 .

AMA Style

Eric Villeneuve, Christophe Volat, Sebastian Ghinet. Numerical and Experimental Investigation of the Design of a Piezoelectric De-Icing System for Small Rotorcraft Part 3/3: Numerical Model and Experimental Validation of Vibration-Based De-Icing of a Flat Plate Structure. Aerospace. 2020; 7 (5):54.

Chicago/Turabian Style

Eric Villeneuve; Christophe Volat; Sebastian Ghinet. 2020. "Numerical and Experimental Investigation of the Design of a Piezoelectric De-Icing System for Small Rotorcraft Part 3/3: Numerical Model and Experimental Validation of Vibration-Based De-Icing of a Flat Plate Structure." Aerospace 7, no. 5: 54.

Journal article
Published: 28 April 2020 in Aerospace
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The objective of this research project is divided in four parts: (1) to design a piezoelectric actuator based de-icing system integrated to a flat plate experimental setup, develop a numerical model of the system and validate experimentally; (2) use the experimental setup to investigate actuator activation with frequency sweeps and transient vibration analysis; (3) add an ice layer to the numerical model, predict numerically stresses at ice breaking and validate experimentally; and (4) implement the concept to a blade structure for wind tunnel testing. This paper presents the second objective of this study, in which the experimental setup designed in the first phase of the project is used to study transient vibration occurring during frequency sweeps. Acceleration during different frequency sweeps was measured with an accelerometer on the flat plate setup. The results obtained showed that the vibration pattern was the same for the different sweep rate (in Hz/s) tested for a same sweep range. However, the amplitude of each resonant mode increased with a sweep rate decrease. Investigation of frequency sweeps performed around different resonant modes showed that as the frequency sweep rate tends towards zero, the amplitude of the mode tends toward the steady-state excitation amplitude value. Since no other transient effects were observed, this signifies that steady-state activation is the optimal excitation for a resonant mode. To validate this hypothesis, the flat plate was installed in a cold room where ice layers were accumulated. Frequency sweeps at high voltage were performed and a camera was used to record multiple pictures per second to determine the frequencies where breaking of the ice occur. Consequently, the resonant frequencies were determined from the transfer functions measured with the accelerometer versus the signal of excitation. Additional tests were performed in steady-state activation at those frequencies and the same breaking of the ice layer was obtained, resulting in the first ice breaking obtained in steady-state activation conditions as part of this research project. These results confirmed the conclusions obtained following the transient vibration investigation, but also demonstrated the drawbacks of steady-state activation, namely identifying resonant modes susceptible of creating ice breaking and locating with precision the frequencies of the modes, which change as the ice accumulates on the structure. Results also show that frequency sweeps, if designed properly, can be used as substitute to steady-state activation for the same results.

ACS Style

Eric Villeneuve; Christophe Volat; Sebastian Ghinet. Numerical and Experimental Investigation of the Design of a Piezoelectric De-Icing System for Small Rotorcraft Part 2/3: Investigation of Transient Vibration during Frequency Sweeps and Optimal Piezoelectric Actuator Excitation. Aerospace 2020, 7, 49 .

AMA Style

Eric Villeneuve, Christophe Volat, Sebastian Ghinet. Numerical and Experimental Investigation of the Design of a Piezoelectric De-Icing System for Small Rotorcraft Part 2/3: Investigation of Transient Vibration during Frequency Sweeps and Optimal Piezoelectric Actuator Excitation. Aerospace. 2020; 7 (5):49.

Chicago/Turabian Style

Eric Villeneuve; Christophe Volat; Sebastian Ghinet. 2020. "Numerical and Experimental Investigation of the Design of a Piezoelectric De-Icing System for Small Rotorcraft Part 2/3: Investigation of Transient Vibration during Frequency Sweeps and Optimal Piezoelectric Actuator Excitation." Aerospace 7, no. 5: 49.

Journal article
Published: 08 April 2020 in Aerospace
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Deicing and anti-icing the aircraft using proper chemical fluids, prior takeoff, are mandatory. A thin layer of ice or snow can compromise the safety, causing lift loss and drag increase. Commercialized deicing and anti-icing fluids all pass a qualification process which is described in Society of Automotive Engineering (SAE) documents. Most of them are endurance time tests under freezing and frozen contaminants, under simulated and natural conditions. They all have in common that the endurance times have to be determined by visual inspection. When a certain proportion of the test plate is covered with contaminants, the endurance time test is called. In the goal of minimizing human error resulting from visual inspection and helping in the interpretation of fluid failure, help-decision computer-assisted algorithms have been developed and tested under different conditions. The algorithms are based on common image processing techniques. The algorithms have been tested under three different icing conditions, water spray endurance test, indoor snow test and light freezing rain tests, and were compared to the times determined by three experimented technicians. A total of 14 tests have been compared. From them, 11 gave a result lower than 5% of the results given by the technicians. In conclusion, the computer-assisted algorithms developed are efficient enough to support the technicians in their failure call. However, further works need to be performed to improve the analysis.

ACS Style

David Gagnon; Jean-Denis Brassard; Hassan Ezzaidi; Christophe Volat. Computer-Assisted Aircraft Anti-Icing Fluids Endurance Time Determination. Aerospace 2020, 7, 39 .

AMA Style

David Gagnon, Jean-Denis Brassard, Hassan Ezzaidi, Christophe Volat. Computer-Assisted Aircraft Anti-Icing Fluids Endurance Time Determination. Aerospace. 2020; 7 (4):39.

Chicago/Turabian Style

David Gagnon; Jean-Denis Brassard; Hassan Ezzaidi; Christophe Volat. 2020. "Computer-Assisted Aircraft Anti-Icing Fluids Endurance Time Determination." Aerospace 7, no. 4: 39.

Journal article
Published: 21 January 2020 in Energies
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This paper presents results based on direct experimental measurements of tangential (Et) and normal (En) E-field components along the stress grading system (SGS) of a real stator bar (Roebel type) for different AC 60 Hz applied voltages. These measurements were made with a new electro-optic system allowing for the study of both spatial distributions of two E-field components along the bar and their temporal evolution at critical points. The results obtained allowed us to calculate the correlation between the distribution of En and Et along the SGS. In particular, it was demonstrated that the En distribution presents a characteristic minimum, which can be used to identify the zone of partial discharge inception. Moreover, it was possible to observe an enlargement of the Et component distribution followed by a saturation in magnitude with the applied voltage increase. Moreover, the results have demonstrated that the waveform of the En component is mostly affected by the SG material used, producing a greater distortion in its waveform than those obtained for the Et component. The more significant distortion was obtained at the end of the outer corona protection (OCP) material, corresponding to the first maximum of the En component and characterized by the appearance of a third harmonic of large amplitude.

ACS Style

Gbah Koné; Christophe Volat; Claude Hudon; And Simon Bernier. Experimental Investigation of the Spatial and Temporal Evolution of the Tangential and Normal E-Field Components along the Stress Grading System of a Real Stator Bar. Energies 2020, 13, 534 .

AMA Style

Gbah Koné, Christophe Volat, Claude Hudon, And Simon Bernier. Experimental Investigation of the Spatial and Temporal Evolution of the Tangential and Normal E-Field Components along the Stress Grading System of a Real Stator Bar. Energies. 2020; 13 (3):534.

Chicago/Turabian Style

Gbah Koné; Christophe Volat; Claude Hudon; And Simon Bernier. 2020. "Experimental Investigation of the Spatial and Temporal Evolution of the Tangential and Normal E-Field Components along the Stress Grading System of a Real Stator Bar." Energies 13, no. 3: 534.

Journal article
Published: 09 October 2019 in Aerospace
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The Anti-icing Materials International Laboratory (AMIL) has been testing SAE AMS1424 and AMS1428 ground de-icing/anti-icing fluids for more than 30 years. With the introduction of new surface coatings and their investigation as potential passive ice protection systems, or for hybrid use with other methods, it is important to understand their interaction with the ground de-icing/anti-icing fluids prior to applications on aircraft. In this study, five different surface coatings, both commercially available and under development, have been tested under two current test methods used to qualify the ground de-icing/anti-icing fluids: The Water Spray Endurance Test (WSET) and the Aerodynamic Acceptance Test (AAT). The tests were performed on three existing commercial de-icing/anti-icing fluids. The results have shown that the coatings tested in this study can considerably reduce the endurance time of the fluids and affect their ability to spread and wet the test surface. Superhydrophobic 1 coating also reduced the aerodynamic penalties created by the Ref. Fluid. Surface coatings, no matter their nature, can impact the performances and behaviour of the fluids and should be thoroughly tested before their use in the industry. The conclusions and methodology of this study were used in the development of sections of the SAE AIR6232 Aircraft Surface Coating Interaction with the Aircraft Deicing/Anti-Icing Fluids standard.

ACS Style

Eric Villeneuve; Jean-Denis Brassard; Christophe Volat. Effect of Various Surface Coatings on De-Icing/Anti-Icing Fluids Aerodynamic and Endurance Time Performances. Aerospace 2019, 6, 114 .

AMA Style

Eric Villeneuve, Jean-Denis Brassard, Christophe Volat. Effect of Various Surface Coatings on De-Icing/Anti-Icing Fluids Aerodynamic and Endurance Time Performances. Aerospace. 2019; 6 (10):114.

Chicago/Turabian Style

Eric Villeneuve; Jean-Denis Brassard; Christophe Volat. 2019. "Effect of Various Surface Coatings on De-Icing/Anti-Icing Fluids Aerodynamic and Endurance Time Performances." Aerospace 6, no. 10: 114.

Journal article
Published: 18 October 2018 in Energies
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This paper investigates the influence of arc velocity and propagation criteria on the parameters of a dynamic numerical mono-arc model used to predict flashover voltage of ice-covered insulators. For that purpose, a generic algorithm has been developed which, coupled with a Finite Element commercial software, permits us to solve the mono-arc Obenaus equation. The versatility of the proposed algorithm allows to implement three different arc propagation criteria and five different arc velocity criteria, as well as to compute the corresponding flashover voltage, arc velocity and leakage current. Moreover, this algorithm permits to propose a new arc velocity criterion based on numerical calculation instead of analytical formulation as proposed in literature.

ACS Style

Marouane Jabbari; Christophe Volat; Issouf Fofana. Numerical Modelling of Ice-Covered Insulator Flashover: The Influence of Arc Velocity and Arc Propagation Criteria. Energies 2018, 11, 2807 .

AMA Style

Marouane Jabbari, Christophe Volat, Issouf Fofana. Numerical Modelling of Ice-Covered Insulator Flashover: The Influence of Arc Velocity and Arc Propagation Criteria. Energies. 2018; 11 (10):2807.

Chicago/Turabian Style

Marouane Jabbari; Christophe Volat; Issouf Fofana. 2018. "Numerical Modelling of Ice-Covered Insulator Flashover: The Influence of Arc Velocity and Arc Propagation Criteria." Energies 11, no. 10: 2807.

Journal article
Published: 17 October 2018 in Energies
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This paper presents the development of a new bi-arc dynamic numerical model for predicting AC critical flashover voltage (FOV) of ice-covered extra-high voltage (EHV) insulators. The proposed model is based on a generic calculation algorithm coupled with commercial finite element method software designed to solve the Obenaus/Rizk model. The proposed model allows one to implement the Nottingham and Mayr approaches and compare the results obtained as a function of the arcing distance, the freezing water conductivity, and the initial arc length. The validation of the model demonstrated high accuracy in predicting the FOV of ice-covered post-type insulators and its capability to simulate the interaction of the two partial arcs during the flashover process. In particular, the results showed that the Nottingham approach is sensibly more accurate than the Mayr one, especially in simulating the dynamic behavior of the partial arcs during the flashover process. Based on the encouraging results obtained, a multi-arc calculation algorithm was proposed using the bi-arc dynamic numerical model as a basis. The basic idea, which consists in dividing the multi-arc model in several bi-arc modules, was not implemented and validated but will serve as a promising concept for future work.

ACS Style

Marouane Jabbari; Christophe Volat; Issouf Fofana. Development of a New Bi-Arc Dynamic Numerical Model for Modeling AC Flashover Processes of EHV Ice-Covered Insulators. Energies 2018, 11, 2792 .

AMA Style

Marouane Jabbari, Christophe Volat, Issouf Fofana. Development of a New Bi-Arc Dynamic Numerical Model for Modeling AC Flashover Processes of EHV Ice-Covered Insulators. Energies. 2018; 11 (10):2792.

Chicago/Turabian Style

Marouane Jabbari; Christophe Volat; Issouf Fofana. 2018. "Development of a New Bi-Arc Dynamic Numerical Model for Modeling AC Flashover Processes of EHV Ice-Covered Insulators." Energies 11, no. 10: 2792.

Research article
Published: 01 December 2017 in High Voltage
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This paper presents an exhaustive study of numerical investigations based on three-dimensional finite-element method modelling of several non-ceramic insulators of 69, 110 and 230 kV having different internal semi-conductive defects in terms of size and position. The internal defects were positioned close to the high-voltage electrode, the ground electrode and at floating potential. The simulations effected on the distortion of the axial and radial E-field components close to the insulator shank between sheds. The results obtained showed that the radial E-field component is more sensitive to the presence of an internal defect as it shows a greater distortion in presence of the defect. It was also observed that the E-field component distortion increases with longer internal defect and that this increase is particularly important for a defect at floating potential. Moreover, it was demonstrated that the length of the insulator, for a defect of constant length, has no significant influence on the E-field component distortion. Finally, the results demonstrated that the presence of a grading ring, as used on the 230 kV insulator, does not have any influence on the E-field component distortion, independently of the defect position.

ACS Style

Gbah Kone; Christophe Volat; Hassan Ezzaidi. Numerical investigation of electric field distortion induced by internal defects in composite insulators. High Voltage 2017, 2, 253 -260.

AMA Style

Gbah Kone, Christophe Volat, Hassan Ezzaidi. Numerical investigation of electric field distortion induced by internal defects in composite insulators. High Voltage. 2017; 2 (4):253-260.

Chicago/Turabian Style

Gbah Kone; Christophe Volat; Hassan Ezzaidi. 2017. "Numerical investigation of electric field distortion induced by internal defects in composite insulators." High Voltage 2, no. 4: 253-260.