The Experts below are selected from a list of 136419 Experts worldwide ranked by ideXlab platform

A. Abdelkefi - One of the best experts on this subject based on the ideXlab platform.

  • Conceptual design and optimization of a tilt-rotor micro air vehicle
    Elsevier, 2019
    Co-Authors: M. Hassanalian, R. Salazar, A. Abdelkefi
    Abstract:

    The conceptual design and optimization of a tilt-rotor Micro Air Vehicle (MAV) for a well-defined mission are performed. The objective of this design cycle is to decrease the design time in order to efficiently create a functional tilt-rotor drone. A flight mission is firstly defined for a tilt-rotor MAV performing hovering and cruise flight scenarios. Secondly, a complex wing shape is chosen and modeled in order to determine the final shape. The initial shape is scaled in order to acquire an arbitrary wingspan of one meter. For the specific area and wingspan, the aspect ratio of the designed wing shape is found to be equal to 2.32. Thirdly, a Constraint Analysis of the MAV is performed by using an energy balance Analysis for six different flight scenarios. This Analysis yields the required power loading and wing loading. Fourthly, the weight of the vehicle is estimated using both statistical and computational methods. After estimating the total weight and the wing loading of the MAV, the surface of the wing is determined, yielding a final wingspan of 0.76 m. Subsequently, considering the total weight of the designed MAV, the needed lift coefficient is determined. Fifthly, using the lift coefficient in conjunction with XLFR5, a batch of airfoils is selected and analyzed to evaluate the aerodynamic coefficients of the wing with each airfoil. This Analysis ultimately leads to the optimum airfoil being selected. Finally, design of the fuselage and tail, internal components selection, and servo-mechanisms design are carried out prior to a stability Analysis. All these proposed steps are needed to design efficient and functional tilt-rotor MAVs. Keywords: Aerodynamic Analysis, Sizing, Tilt-rotor MAV, VTOL, Stabilit

  • Design, manufacturing, and flight testing of a fixed wing micro air vehicle with Zimmerman planform
    Meccanica, 2017
    Co-Authors: M. Hassanalian, A. Abdelkefi
    Abstract:

    An optimized and comprehensive method is used to design and manufacture a fixed wing micro air vehicle (MAV) with Zimmerman planform. The design process includes four stages which are the specification of the flight mission, determination of the best aspect ratio, identification of the optimum wing loading and thrust loading values, and estimation of the weight of the structural components of the MAV. To do this, various statistical and analytical methods are utilized. Based on an aerodynamic Analysis, the results show that an optimum aspect ratio that maximizes the performance of the Zimmerman MAV for a well-defined cruise speed is determined. Considering six possible flights, a Constraint Analysis is performed and an optimum wing loading value is determined. It is shown that the computational method is beneficial to determine the exact masses for the structural components including the wing, fuselage, and vertical tail. Using the 3D panel method, the determination of the shape of the reflexed airfoil for the MAV is successfully done by minimizing the drag force and the angle of attack to use less powerful motor and avoid any stall effect, respectively. A stability Analysis is then performed to check the safe flight of the designed vehicle. During test flight, the results show that the designed Zimmerman MAV satisfies the pre-defined specification. The final characteristics of the manufactured MAV are: wingspan of 44 cm, weight of 450 g, aspect ratio of 1.51, cruise speed of 20 m/s, and flight endurance of 20 min.

M. Hassanalian - One of the best experts on this subject based on the ideXlab platform.

  • Conceptual design and optimization of a tilt-rotor micro air vehicle
    Elsevier, 2019
    Co-Authors: M. Hassanalian, R. Salazar, A. Abdelkefi
    Abstract:

    The conceptual design and optimization of a tilt-rotor Micro Air Vehicle (MAV) for a well-defined mission are performed. The objective of this design cycle is to decrease the design time in order to efficiently create a functional tilt-rotor drone. A flight mission is firstly defined for a tilt-rotor MAV performing hovering and cruise flight scenarios. Secondly, a complex wing shape is chosen and modeled in order to determine the final shape. The initial shape is scaled in order to acquire an arbitrary wingspan of one meter. For the specific area and wingspan, the aspect ratio of the designed wing shape is found to be equal to 2.32. Thirdly, a Constraint Analysis of the MAV is performed by using an energy balance Analysis for six different flight scenarios. This Analysis yields the required power loading and wing loading. Fourthly, the weight of the vehicle is estimated using both statistical and computational methods. After estimating the total weight and the wing loading of the MAV, the surface of the wing is determined, yielding a final wingspan of 0.76 m. Subsequently, considering the total weight of the designed MAV, the needed lift coefficient is determined. Fifthly, using the lift coefficient in conjunction with XLFR5, a batch of airfoils is selected and analyzed to evaluate the aerodynamic coefficients of the wing with each airfoil. This Analysis ultimately leads to the optimum airfoil being selected. Finally, design of the fuselage and tail, internal components selection, and servo-mechanisms design are carried out prior to a stability Analysis. All these proposed steps are needed to design efficient and functional tilt-rotor MAVs. Keywords: Aerodynamic Analysis, Sizing, Tilt-rotor MAV, VTOL, Stabilit

  • Design, manufacturing, and flight testing of a fixed wing micro air vehicle with Zimmerman planform
    Meccanica, 2017
    Co-Authors: M. Hassanalian, A. Abdelkefi
    Abstract:

    An optimized and comprehensive method is used to design and manufacture a fixed wing micro air vehicle (MAV) with Zimmerman planform. The design process includes four stages which are the specification of the flight mission, determination of the best aspect ratio, identification of the optimum wing loading and thrust loading values, and estimation of the weight of the structural components of the MAV. To do this, various statistical and analytical methods are utilized. Based on an aerodynamic Analysis, the results show that an optimum aspect ratio that maximizes the performance of the Zimmerman MAV for a well-defined cruise speed is determined. Considering six possible flights, a Constraint Analysis is performed and an optimum wing loading value is determined. It is shown that the computational method is beneficial to determine the exact masses for the structural components including the wing, fuselage, and vertical tail. Using the 3D panel method, the determination of the shape of the reflexed airfoil for the MAV is successfully done by minimizing the drag force and the angle of attack to use less powerful motor and avoid any stall effect, respectively. A stability Analysis is then performed to check the safe flight of the designed vehicle. During test flight, the results show that the designed Zimmerman MAV satisfies the pre-defined specification. The final characteristics of the manufactured MAV are: wingspan of 44 cm, weight of 450 g, aspect ratio of 1.51, cruise speed of 20 m/s, and flight endurance of 20 min.

Mostafa Hassanalian - One of the best experts on this subject based on the ideXlab platform.

  • conceptual design and optimization of a tilt rotor micro air vehicle
    Chinese Journal of Aeronautics, 2019
    Co-Authors: Mostafa Hassanalian, R. Salazar, Abdessattar Abdelkefi
    Abstract:

    Abstract The conceptual design and optimization of a tilt-rotor Micro Air Vehicle (MAV) for a well-defined mission are performed. The objective of this design cycle is to decrease the design time in order to efficiently create a functional tilt-rotor drone. A flight mission is firstly defined for a tilt-rotor MAV performing hovering and cruise flight scenarios. Secondly, a complex wing shape is chosen and modeled in order to determine the final shape. The initial shape is scaled in order to acquire an arbitrary wingspan of one meter. For the specific area and wingspan, the aspect ratio of the designed wing shape is found to be equal to 2.32. Thirdly, a Constraint Analysis of the MAV is performed by using an energy balance Analysis for six different flight scenarios. This Analysis yields the required power loading and wing loading. Fourthly, the weight of the vehicle is estimated using both statistical and computational methods. After estimating the total weight and the wing loading of the MAV, the surface of the wing is determined, yielding a final wingspan of 0.76 m. Subsequently, considering the total weight of the designed MAV, the needed lift coefficient is determined. Fifthly, using the lift coefficient in conjunction with XLFR5, a batch of airfoils is selected and analyzed to evaluate the aerodynamic coefficients of the wing with each airfoil. This Analysis ultimately leads to the optimum airfoil being selected. Finally, design of the fuselage and tail, internal components selection, and servo-mechanisms design are carried out prior to a stability Analysis. All these proposed steps are needed to design efficient and functional tilt-rotor MAVs.

  • a novel methodology for wing sizing of bio inspired flapping wing micro air vehicles theory and prototype
    Acta Mechanica, 2017
    Co-Authors: Mostafa Hassanalian, Abdessattar Abdelkefi, Mingjun Wei, S Ziaeirad
    Abstract:

    To design efficient flapping wing micro air vehicles (FWMAVs), a comprehensive sizing method based on theoretical and statistical analyses is proposed and experimentally verified. This method is composed of five steps including defining and analyzing the MAV mission, determining the flying modes, defining the wing shape and aspect ratio of the wing, applying the Constraint Analysis based on the defined mission, and estimating the weights of the electrical and structural components of the bio-inspired flapping wing micro air vehicle. To define the vehicle mission and flight plan, path Analysis is performed based on the defined mission, the speed of cruise and turning, the turning radius and climatic conditions in the flight area. Following the defined mission Analysis, the appropriate modes of flying (i.e., flapping, gliding, hovering, bounding, and soaring) for the flapping wing bird are recognized. After that, the wing shape and the wing aspect ratio are determined based on the defined flight modes. To estimate the wing loading, a Constraint Analysis is exploited in which flight equitation is simulated based on the modes and missions of the flight. Along with the four listed steps, a statistical method is employed to estimate the FWMAV weight for a well-defined mission. Based on the offered method for wing sizing of flapping wings, a FWMAV named Thunder I has been designed, fabricated, and tested. This developed methodology is very beneficial by giving guidelines for the design of efficient bio-inspired FWMAVs.

Jen Q Pan - One of the best experts on this subject based on the ideXlab platform.

  • biological concepts in human sodium channel epilepsies and their relevance in clinical practice
    Epilepsia, 2020
    Co-Authors: Andreas Brunklaus, Felix Steckler, Ismael I Ghanty, Katrine M Johannesen, Christina Fenger, Stephanie Schorge, David Baeznieto, Haoran Wang, Andrew Allen, Jen Q Pan
    Abstract:

    Objective Voltage-gated sodium channels (SCNs) share similar amino acid sequence, structure, and function. Genetic variants in the four human brain-expressed SCN genes SCN1A/2A/3A/8A have been associated with heterogeneous epilepsy phenotypes and neurodevelopmental disorders. To better understand the biology of seizure susceptibility in SCN-related epilepsies, our aim was to determine similarities and differences between sodium channel disorders, allowing us to develop a broader perspective on precision treatment than on an individual gene level alone. Methods We analyzed genotype-phenotype correlations in large SCN-patient cohorts and applied variant Constraint Analysis to identify severe sodium channel disease. We examined temporal patterns of human SCN expression and correlated functional data from in vitro studies with clinical phenotypes across different sodium channel disorders. Results Comparing 865 epilepsy patients (504 SCN1A, 140 SCN2A, 171 SCN8A, four SCN3A, 46 copy number variation [CNV] cases) and Analysis of 114 functional studies allowed us to identify common patterns of presentation. All four epilepsy-associated SCN genes demonstrated significant Constraint in both protein truncating and missense variation when compared to other SCN genes. We observed that age at seizure onset is related to SCN gene expression over time. Individuals with gain-of-function SCN2A/3A/8A missense variants or CNV duplications share similar characteristics, most frequently present with early onset epilepsy (<3 months), and demonstrate good response to sodium channel blockers (SCBs). Direct comparison of corresponding SCN variants across different SCN subtypes illustrates that the functional effects of variants in corresponding channel locations are similar; however, their clinical manifestation differs, depending on their role in different types of neurons in which they are expressed. Significance Variant function and location within one channel can serve as a surrogate for variant effects across related sodium channels. Taking a broader view on precision treatment suggests that in those patients with a suspected underlying genetic epilepsy presenting with neonatal or early onset seizures (<3 months), SCBs should be considered.

Abdessattar Abdelkefi - One of the best experts on this subject based on the ideXlab platform.

  • conceptual design and optimization of a tilt rotor micro air vehicle
    Chinese Journal of Aeronautics, 2019
    Co-Authors: Mostafa Hassanalian, R. Salazar, Abdessattar Abdelkefi
    Abstract:

    Abstract The conceptual design and optimization of a tilt-rotor Micro Air Vehicle (MAV) for a well-defined mission are performed. The objective of this design cycle is to decrease the design time in order to efficiently create a functional tilt-rotor drone. A flight mission is firstly defined for a tilt-rotor MAV performing hovering and cruise flight scenarios. Secondly, a complex wing shape is chosen and modeled in order to determine the final shape. The initial shape is scaled in order to acquire an arbitrary wingspan of one meter. For the specific area and wingspan, the aspect ratio of the designed wing shape is found to be equal to 2.32. Thirdly, a Constraint Analysis of the MAV is performed by using an energy balance Analysis for six different flight scenarios. This Analysis yields the required power loading and wing loading. Fourthly, the weight of the vehicle is estimated using both statistical and computational methods. After estimating the total weight and the wing loading of the MAV, the surface of the wing is determined, yielding a final wingspan of 0.76 m. Subsequently, considering the total weight of the designed MAV, the needed lift coefficient is determined. Fifthly, using the lift coefficient in conjunction with XLFR5, a batch of airfoils is selected and analyzed to evaluate the aerodynamic coefficients of the wing with each airfoil. This Analysis ultimately leads to the optimum airfoil being selected. Finally, design of the fuselage and tail, internal components selection, and servo-mechanisms design are carried out prior to a stability Analysis. All these proposed steps are needed to design efficient and functional tilt-rotor MAVs.

  • a novel methodology for wing sizing of bio inspired flapping wing micro air vehicles theory and prototype
    Acta Mechanica, 2017
    Co-Authors: Mostafa Hassanalian, Abdessattar Abdelkefi, Mingjun Wei, S Ziaeirad
    Abstract:

    To design efficient flapping wing micro air vehicles (FWMAVs), a comprehensive sizing method based on theoretical and statistical analyses is proposed and experimentally verified. This method is composed of five steps including defining and analyzing the MAV mission, determining the flying modes, defining the wing shape and aspect ratio of the wing, applying the Constraint Analysis based on the defined mission, and estimating the weights of the electrical and structural components of the bio-inspired flapping wing micro air vehicle. To define the vehicle mission and flight plan, path Analysis is performed based on the defined mission, the speed of cruise and turning, the turning radius and climatic conditions in the flight area. Following the defined mission Analysis, the appropriate modes of flying (i.e., flapping, gliding, hovering, bounding, and soaring) for the flapping wing bird are recognized. After that, the wing shape and the wing aspect ratio are determined based on the defined flight modes. To estimate the wing loading, a Constraint Analysis is exploited in which flight equitation is simulated based on the modes and missions of the flight. Along with the four listed steps, a statistical method is employed to estimate the FWMAV weight for a well-defined mission. Based on the offered method for wing sizing of flapping wings, a FWMAV named Thunder I has been designed, fabricated, and tested. This developed methodology is very beneficial by giving guidelines for the design of efficient bio-inspired FWMAVs.