Elastic Torsion Effects on Helicopter Rotor loading in Forward Flight

Dayhoum, Abdallah; Zakaria, Mohamed Y.; Abdelhamid, O. E.

doi:10.2514/6.2020-0507

Cited by 4 publications

(2 citation statements)

References 11 publications

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“…On the other hand, fluid structure interaction modeling became essential for solving flow around vibrating and rotating structure [7,[20][21][22]. Modeling such moving bodies requires aerodynamic unsteady nonlinear models to assure accuracy in modeling results rather than using quazi-steady models.…”

Section: Figurementioning

confidence: 99%

Unsteady Aerodynamics of Highly Maneuvering Flyers

Zakaria¹

2021

Biomimetics

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In this chapter, a set of analytical aerodynamic models, based on potential flow, that can be used to predict the unsteady lift response during pitching maneuvers are presented and assessed. The result examines the unsteady lift coefficients experienced by a flat plate in high-amplitude pitch ramp motion. The pitch ramps are chosen based on two ramp pitch maneuvers of a maximum amplitudes of 25 and 45 degrees starting from zero degree. The aim is investigate the use of such classical models in predicting the lift dynamics compared to a full physical-based model. Among all classical methods used, the unsteady vortex lattice method (without considering the leading edge vortex) is found to be a very good predictor of the motion lift dynamic response for the 25° ramp angle case. However, at high pitch maneuvers (i.e.,the 45° ramp angle case), could preserve the response pattern with attenuated amplitudes without high computational burden. These mathematical analytical models presented in this chapter can be used to obtain a fast estimate for aircraft unsteady lift during pitch maneuvers instead of high fidelity models, especially in the early design phases.

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Section: Figurementioning

confidence: 99%

Unsteady Aerodynamics of Highly Maneuvering Flyers

Zakaria¹

2021

Biomimetics

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“…For this, computational Fluid Dynamics (CFD) combined with shroud design and rotor/motor selection are considered crucial. The principal objectives of the motor selection criteria endeavor encompass the enhancement of hover endurance, payload capacity, and overall robustness [9,10,11].…”

Section: Introductionmentioning

confidence: 99%

Enhancing VTOL Performance: Shrouded Rotor BLDC Motor Model and Validation

Dayhoum,

Etewa,

Ramirez-Serrano

et al. 2024

J. Phys.: Conf. Ser.

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One prominent area of current research interest, driven by a multitude of factors and considerations, centers around drone technology. A primary challenge currently faced in the realm of small-scale Unmanned Aerial Vehicles (UAVs) is the increasing demand for increased power coupled with the constraint of limited flight duration provided by available battery technology. These vehicles fall into two overarching categories based on the presence or absence of shrouding around their rotor(s). Shrouded rotors play a pivotal role in augmenting aerodynamic performance by enhancing thrust while mitigating blade-tip vortex losses and numerous other aspects that are not presented in open rotors. Although such characteristics contribute to an expanded effective rotor diameter and optimized airflow within the shroud. There are numerous aspects related to power, shroud and rotor characterization, etc. that need to be understood before shrouded rotors are commonly used. This paper presents the implementation of an effective mathematical model for Brushless Direct Current (BLDC) motors, specifically tailored for application in conjunction with shrouded rotors aimed at enhancing thrust and reducing power consumption. The proposed model serves to predict the performance characteristics of the utilized motor within the context of the specified shrouded rotor combination. In order to identify the effects of the induced load torque on the rotor’s dynamic response, a methodical analysis is conducted on the numerical simulation of the proposed model. The results are experimentally verified for hover flying in a case study of a scalable and highly maneuverable vertical takeoff and landing aircraft developed for operations in highly confined spaces. The adoption of this modeling technique is anticipated to significantly streamline the shrouded rotor combination design and selection process, particularly in the selection of an appropriate motor.

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