The Experts below are selected from a list of 294 Experts worldwide ranked by ideXlab platform
Michael J R Graham - One of the best experts on this subject based on the ideXlab platform.
-
applications of the unsteady vortex lattice method in aircraft aeroelasticity and flight dynamics
Progress in Aerospace Sciences, 2012Co-Authors: Joseba Murua, Rafael Palacios, Michael J R GrahamAbstract:The Unsteady Vortex-Lattice Method provides a Medium-Fidelity tool for the prediction of non-stationary aerodynamic loads in low-speed, but high-Reynolds-number, attached flow conditions. Despite a proven track record in applications where free-wake modelling is critical, other less-computationally-expensive potential-flow models, such as the Doublet-Lattice Method and strip theory, have long been favoured in fixed-wing aircraft aeroelasticity and flight dynamics. This paper presents how the Unsteady Vortex-Lattice Method can be implemented as an enhanced alternative to those techniques for diverse situations that arise in flexible-aircraft dynamics. A historical review of the methodology is included, with latest developments and practical applications. Di erent formulations of the aerodynamic equations are outlined, and they are integrated with a nonlinear beam model for the full description of the dynamics of a free-flying flexible vehicle. Nonlinear time-marching solutions capture large wing excursions and wake roll-up, and the linearisation of the equations lends itself to a seamless, monolithic state-space assembly, particularly convenient for stability analysis and flight control system design. The numerical studies emphasise scenarios where the Unsteady Vortex-Lattice Method can provide an advantage over other state-of-the-art approaches. Examples of this include unsteady aerodynamics in vehicles with coupled aeroelasticity and flight dynamics, and in lifting surfaces undergoing complex kinematics, large deformations, or in-plane motions. Geometric nonlinearities are shown to play an instrumental, and often counter-intuitive, role in the aircraft dynamics. The Unsteady Vortex-Lattice Method is unveiled as a remarkable tool that can successfully incorporate all those e ects in the unsteady aerodynamics modelling.
Sarah N Bowe - One of the best experts on this subject based on the ideXlab platform.
-
construct validity of a low cost Medium Fidelity endoscopic sinus surgery simulation model
Laryngoscope, 2019Co-Authors: Yuki Yoshiyasu, Daniel R Chang, Leonid Bunegin, Ryan P Lin, James K Aden, Thomas J Prihoda, Erik K Weitzel, Kevin C Mcmains, Sonya Malekzadeh, Sarah N BoweAbstract:Objective Assess construct validity of a low-cost Medium-Fidelity silicone injection molded model task trainer for endoscopic sinus surgery (ESS) training. Methods Fellowship-trained rhinologists, otolaryngology attendings, and otolaryngology residents at various levels of training performed sinus endoscopy and seven procedures on the model. Construct validity was evaluated by comparing novice to various levels of experienced performance using a validated checklist. Results Thirty-two subjects participated in this study. Otolaryngology attendings and postgraduate year (PGY) 3 to 5 otolaryngology residents significantly outperformed PGY 1 to 2 otolaryngology residents on most tasks in the task-specific checklist. Conclusions This study demonstrated the construct validity of the low-cost Medium-Fidelity ESS model. Level of evidence NA Laryngoscope, 129:1505-1509, 2019.
-
fabrication and validation of a low cost Medium Fidelity silicone injection molded endoscopic sinus surgery simulation model
Laryngoscope, 2017Co-Authors: Daniel R Chang, Leonid Bunegin, Erik K Weitzel, Kevin C Mcmains, Sarah N Bowe, Thomas J Willson, Philip G ChenAbstract:OBJECTIVES/HYPOTHESIS: Develop a low-cost, Medium-Fidelity model for education in endoscopic sinus surgery techniques. Establish face and content validity of the model based on the feedback of otolaryngology faculty including fellowship-trained rhinologists. STUDY DESIGN: Survey. METHODS: A novel silicone injection molded sinus model was constructed. Three fellowship-trained rhinologists and four general otolaryngologists were recruited to perform seven tasks and provide feedback of the model's performance via a 22-question Likert survey. RESULTS: Those surveyed strongly agreed the sinus model is useful for basic endoscopic skill acquisition such as camera skills (86%), hand-eye coordination (100%), nasal endoscopy skills (100%). Ratings of the model for training the specific tasks were consistently high. Neutral or lower were received for inferior turbinoplasty (14%), frontal balloon task (14%), understanding the ethmoid bulla (29%), and advanced sinus techniques (57%). All faculty strongly agreed they would be interested in using the model to train residents. CONCLUSIONS: Simulation models have proven efficacy in endoscopic skill and procedural training. The group developed a novel low-cost, Medium-Fidelity sinus training model utilizing three-dimensional modeling and printing. Testing of this model revealed high ratings for both face and construct validity for a range of endoscopic procedures. Strong interest in using this model for resident training was unanimous among all survey participants. LEVEL OF EVIDENCE: NA Laryngoscope, 127:781-786, 2017.
Annie Ross - One of the best experts on this subject based on the ideXlab platform.
-
comparison of low Medium and high Fidelity numerical methods for unsteady aerodynamics and nonlinear aeroelasticity
Journal of Fluids and Structures, 2019Co-Authors: Claudia Fernandezescudero, Miguel Gagnon, Eric Laurendeau, Sebastien Prothin, Guilhem Michon, Annie RossAbstract:Abstract The unsteady aerodynamic and aeroelastic behavior of a 2D wing section with and without flap is analyzed with Theodorsen theory and Unsteady Vortex Lattice Method (low Fidelity), Euler (Medium Fidelity) and Reynolds-Averaged Navier Stokes (high Fidelity) methods. The aeroelastic studies are carried out for linear cases and non-linear structural configurations presenting cubic stiffness and freeplay. The critical flutter speeds as well as the limit cycle oscillations present in the non-linear cases are compared. The methods show good agreement for the cases studied.
Daniel R Chang - One of the best experts on this subject based on the ideXlab platform.
-
construct validity of a low cost Medium Fidelity endoscopic sinus surgery simulation model
Laryngoscope, 2019Co-Authors: Yuki Yoshiyasu, Daniel R Chang, Leonid Bunegin, Ryan P Lin, James K Aden, Thomas J Prihoda, Erik K Weitzel, Kevin C Mcmains, Sonya Malekzadeh, Sarah N BoweAbstract:Objective Assess construct validity of a low-cost Medium-Fidelity silicone injection molded model task trainer for endoscopic sinus surgery (ESS) training. Methods Fellowship-trained rhinologists, otolaryngology attendings, and otolaryngology residents at various levels of training performed sinus endoscopy and seven procedures on the model. Construct validity was evaluated by comparing novice to various levels of experienced performance using a validated checklist. Results Thirty-two subjects participated in this study. Otolaryngology attendings and postgraduate year (PGY) 3 to 5 otolaryngology residents significantly outperformed PGY 1 to 2 otolaryngology residents on most tasks in the task-specific checklist. Conclusions This study demonstrated the construct validity of the low-cost Medium-Fidelity ESS model. Level of evidence NA Laryngoscope, 129:1505-1509, 2019.
-
fabrication and validation of a low cost Medium Fidelity silicone injection molded endoscopic sinus surgery simulation model
Laryngoscope, 2017Co-Authors: Daniel R Chang, Leonid Bunegin, Erik K Weitzel, Kevin C Mcmains, Sarah N Bowe, Thomas J Willson, Philip G ChenAbstract:OBJECTIVES/HYPOTHESIS: Develop a low-cost, Medium-Fidelity model for education in endoscopic sinus surgery techniques. Establish face and content validity of the model based on the feedback of otolaryngology faculty including fellowship-trained rhinologists. STUDY DESIGN: Survey. METHODS: A novel silicone injection molded sinus model was constructed. Three fellowship-trained rhinologists and four general otolaryngologists were recruited to perform seven tasks and provide feedback of the model's performance via a 22-question Likert survey. RESULTS: Those surveyed strongly agreed the sinus model is useful for basic endoscopic skill acquisition such as camera skills (86%), hand-eye coordination (100%), nasal endoscopy skills (100%). Ratings of the model for training the specific tasks were consistently high. Neutral or lower were received for inferior turbinoplasty (14%), frontal balloon task (14%), understanding the ethmoid bulla (29%), and advanced sinus techniques (57%). All faculty strongly agreed they would be interested in using the model to train residents. CONCLUSIONS: Simulation models have proven efficacy in endoscopic skill and procedural training. The group developed a novel low-cost, Medium-Fidelity sinus training model utilizing three-dimensional modeling and printing. Testing of this model revealed high ratings for both face and construct validity for a range of endoscopic procedures. Strong interest in using this model for resident training was unanimous among all survey participants. LEVEL OF EVIDENCE: NA Laryngoscope, 127:781-786, 2017.
Joseba Murua - One of the best experts on this subject based on the ideXlab platform.
-
applications of the unsteady vortex lattice method in aircraft aeroelasticity and flight dynamics
Progress in Aerospace Sciences, 2012Co-Authors: Joseba Murua, Rafael Palacios, Michael J R GrahamAbstract:The Unsteady Vortex-Lattice Method provides a Medium-Fidelity tool for the prediction of non-stationary aerodynamic loads in low-speed, but high-Reynolds-number, attached flow conditions. Despite a proven track record in applications where free-wake modelling is critical, other less-computationally-expensive potential-flow models, such as the Doublet-Lattice Method and strip theory, have long been favoured in fixed-wing aircraft aeroelasticity and flight dynamics. This paper presents how the Unsteady Vortex-Lattice Method can be implemented as an enhanced alternative to those techniques for diverse situations that arise in flexible-aircraft dynamics. A historical review of the methodology is included, with latest developments and practical applications. Di erent formulations of the aerodynamic equations are outlined, and they are integrated with a nonlinear beam model for the full description of the dynamics of a free-flying flexible vehicle. Nonlinear time-marching solutions capture large wing excursions and wake roll-up, and the linearisation of the equations lends itself to a seamless, monolithic state-space assembly, particularly convenient for stability analysis and flight control system design. The numerical studies emphasise scenarios where the Unsteady Vortex-Lattice Method can provide an advantage over other state-of-the-art approaches. Examples of this include unsteady aerodynamics in vehicles with coupled aeroelasticity and flight dynamics, and in lifting surfaces undergoing complex kinematics, large deformations, or in-plane motions. Geometric nonlinearities are shown to play an instrumental, and often counter-intuitive, role in the aircraft dynamics. The Unsteady Vortex-Lattice Method is unveiled as a remarkable tool that can successfully incorporate all those e ects in the unsteady aerodynamics modelling.