Effects of High Fidelity Modeling of Multirotor Drones

2021 ◽  
Vol 1 (1) ◽  
Author(s):  
Samantha Hoang ◽  
Laurel Marsh ◽  
Alberto Aliseda ◽  
I. Y. Shen

Abstract This paper examines two different factors that will affect energy consumption for multi-rotor drones with more than four rotors. First, the choice of aerodynamic model for the rotor blades is examined. Two aerodynamic models, the blade element theory (BET) model and lumped blade (LB) model, are compared using vertical, roll, pitch, and yaw trajectories. The BET and LB models produced very different trajectories with identical inputs, especially in the vertical and yaw trajectories which differed by 87.9% and 52.5%, respectively. The BET and LB models also result in different energy usages with the LB model consistently predicting 36% more energy consumption. The second factor studied is the choice of rotor groupings. For a multi-rotor drone, different rotor groupings may result in different energy usages; two groupings are considered. The same four basic trajectories are compared. The results show that the two groupings have an energy difference of 4.7–4.9% for each of the roll, pitch, and yaw directions which implies that each grouping has a base energy consumption inherent to it. Then, possible energy compounding effects are explored by examining a complex trajectory. The complex trajectory yields a 9.26% energy difference between the two groupings but further examination reveals that the difference is due to differences in the final trajectory not energy compounding effects. Thus, it is concluded that the aerodynamic model and rotor groupings are two important factors that must be considered when energy consumption needs to be minimized.

2017 ◽  
Vol 11 (2) ◽  
pp. 2711-2722
Author(s):  
M.F. Yaakub ◽  
◽  
A.A. Wahab ◽  
A. Abdullah ◽  
N.A.R. Nik Mohd ◽  
...  

Author(s):  
Sigitas Rimkus ◽  
Tuhin Das

Auto-rotation or autogyro is a well-known phenomenon where a rotor in a wind field generates significant lift while the wind induces considerable aerodynamic torque on the rotor. The principle has been studied extensively for applications in aviation. However, with recent works indicating immense, persistent, and pervasive, available wind energy at high altitudes, the principle of autogyro could potentially be exploited for energy harvesting. In this paper, we carry out a preliminary investigation on the viability of using autogyros for energy extraction. We mainly focus on one of the earliest documented works on modeling of autogyro and extend its use to explore energy harvesting. The model is based on blade element theory. We provide simulation results of the concept. Although the results are encouraging, there are various practical aspects that need to be investigated to build confidence on this approach of energy harvesting. This work aims to build a framework upon which more comprehensive research can be conducted.


2013 ◽  
Vol 385-386 ◽  
pp. 259-262
Author(s):  
Ying Yan ◽  
Ji Hui Zhuang ◽  
Dao Wei Zhu

The relationship between the difference of the driver behavior and energy consumption in the same bus line was studied through analyzing the inlet parking process of the driving cycles in order to solve the problem that the practical benefits in endurance mileage of the electric buses differed a lot. It showed that the energy recycled in the inlet parking process differed 21% between the best driver and the worst one and the energy difference was influenced dramatically by the accuracy of vehicle speed prediction and the tendency of deceleration of drivers.1.


Author(s):  
Timothy A. Burdett ◽  
Kenneth W. Van Treuren

Wind turbines are often designed using some form of Blade Element Model (BEM). However, different models can produce significantly different results when optimizing the angle of twist for power production. This paper compares the theoretical result of optimizing the angle of twist using Blade Element Theory (BET) and Blade Element Momentum Theory (BEMT) with a tip-loss correction for a 3-bladed, 1.15-m diameter wind turbine with a design tip speed ratio (TSR) of 5. These two theories have been chosen because they are readily available to small-scale designers. Additionally, the turbine was scaled for experimental testing in the Baylor Subsonic Wind Tunnel. Angle of twist distributions differed by as much as 15 degrees near the hub, and the coefficient of power differed as much as 0.08 for the wind speeds tested.


Author(s):  
David H. Wood

All rotating blades shed helical vortices which have a significant effect on the velocity over the blades and the forces acting on them. Nevertheless, knowledge of vortex behavior is not used in blade element theory (BET), the most common method to calculate the thrust produced by propellers and the power by wind turbines. Helical vortices of constant pitch and radius are also of fundamental interest as one of only three geometries that do not deform under their “self-induced” motion. This aspect of vortex theory is reviewed historically and the relationship with the forces acting on submerged bodies briefly reviewed. The development of helical vortex theory (HVT) in the 20th century is then described. It is shown that HVT allows BET to be used for a number of important problems that cannot be analyzed by current versions of the theory.


Author(s):  
Kai Zhang ◽  
Onur Bilgen

Abstract This paper presents a comparison of low- and mid-fidelity aerodynamic modelling of floating offshore wind turbine rotors. The low-fidelity approach employs the conventional Blade Element Momentum theory implemented in AeroDyn of OpenFAST. This model ignores the aerodynamic interactions between different blade elements, and the forces on the blade are determined from the balance between momentum theory and blade element theory. With this method, it is possible to calculate the aerodynamic performance for different settings with low computational cost. For the mid-fidelity approach, the Actuator Line Modeling method implemented in turbinesFoam (an OpenFOAM library) is used. This method is built upon a combination of the blade element theory for modeling the blades, and a Navier-Stokes description of the wake flow field. Thus, it can capture the wake dynamics without resolving the detailed flows near the blades. The aerodynamic performance of the DTU 10 MW reference wind turbine rotor is studied using the two methods. The effects of wind speed, tip speed ratio, and blade pitch angles are assessed. Good agreement is observed between the two methods at low tip speed ratios, while the Actuator Line Modeling method predicts slightly higher power coefficients at high tip speed ratios. In addition, the ability of the Actuator Line Modeling Method to capture the wake dynamics of the rotor in an unsteady inflow is demonstrated. In the future, the multi-fidelity aerodynamic modules developed in this paper will be integrated with the hydro-kinematics and hydro-dynamics of a floating platform and a mooring system, to achieve a fully coupled framework for the analysis and design optimization of floating offshore wind turbines.


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