Thrust Modeling and Measurement for Clapping Wing Nano Air Vehicles Actuated by Piezoelectric T-Beams

2010 ◽  
Author(s):  
Kiron Mateti ◽  
Zheqian Zhang ◽  
Srinivas A. Tadigadapa ◽  
Christopher D. Rahn
Keyword(s):  
High Efficiency ◽  
Thrust Force ◽  
High Power Density ◽  
Unsteady Aerodynamic ◽  
Air Vehicle ◽  
And Function ◽  
Three Degree Of Freedom ◽  
Nano Air Vehicle ◽  
T Beam ◽  
Air Vehicles

Insects that use a Weis-Fogh clap and fling mechanism, where their wings clap together and fling apart, show an increase in thrust per unit muscle mass compared to conventional flapping insects. This has motivated the development of macroscale clapping winged ornithopters with four wings. Most clapping wing ornithopters use electric motors with gears and linkages that are inefficient at the sub-millimeter (meso)scale. Piezoelectric actuators are attractive for Nano Air Vehicles (NAVs) because they have high power density, high efficiency, and new fabrication processes have been developed at this scale. Recently developed piezoelectric T-beam actuators are monolithically fabricated from bulk PZT and function like unimorph actuators without the need to bond passive layers. These bending actuators drive a novel four-winged clapping NAV that produces thrust. This paper studies thrust force generation of a clapping wing NAV using a model-based approach. A three degree of freedom dynamic model of the clapping wing nano air vehicle is derived including unsteady aerodynamic forces and torques. The model is validated using experimental data from a NAV prototype.

Clapping Wing Nano Air Vehicle Using Piezoelectric T-Beam Actuators

2009 ◽  
Author(s):  
Kiron Mateti ◽  
Hareesh K. R. Kommepalli ◽  
Srinivas A. Tadigadapa ◽  
Christopher D. Rahn
Keyword(s):  
Vortex Structures ◽  
Air Vehicle ◽  
Nano Air Vehicle ◽  
T Beam ◽  
Wing Stroke ◽  
Air Vehicles

Clapping wing air vehicles are inspired by the Weis-Fogh clap and fling mechanism used by certain insects, where opposing wings almost touch during part of the flap cycle, spawning vortex structures that increase thrust. Current vehicles cannot be scaled to Nano Air Vehicle (NAV) dimensions because they use electromagnetic motors, gears, and linkages that are difficult to fabricate and have poor efficiency at the sub-millimeter scale. This paper develops a novel NAV that uses piezoelectric T-beam actuators that are monolithically fabricated and exhibit unimorph behavior. A hinge and lever wing mechanism amplifies the small actuator displacements to produce large wing motions. A four wing, clapping NAV is designed, fabricated, and experimentally shown to provide a wing stroke angle of approximately 35° at 1 Hz.

scholarly journals Analysis and Pareto Frontier Based Tradeoff Design of an Integrated Magnetic Structure for a CLLC Resonant Converter

Energies ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1756
Author(s):  
Gang Wang ◽  
Qiyu Hu ◽  
Chunyu Xu ◽  
Bin Zhao ◽  
Xiaobao Su
Keyword(s):  
Magnetic Structure ◽  
Power Density ◽  
High Efficiency ◽  
Pareto Frontier ◽  
Optimization Procedure ◽  
Magnetic Core ◽  
Pareto Optimization ◽  
High Power Density ◽  
Resonant Converter ◽  
Conduction Loss

This paper proposes an integrated magnetic structure for a CLLC resonant converter. With the proposed integrated magnetic structure, two resonant inductances and the transformer are integrated into one magnetic core, which improves the power density of the CLLC resonant converter. In the proposed integrated magnetic structure, two resonant inductances are decoupled with the transformer and can be adjusted by the number of turns in each inductance. Furthermore, two resonant inductances are coupled to reduce the number of turns in each inductance. As a result, the conduction loss can be reduced. The trade-off design of the integrated magnetic structure is carried out based on the Pareto optimization procedure. With the Pareto optimization procedure, both high efficiency and high-power density can be achieved. The proposed integrated magnetic structure is validated by theoretical analysis, simulations, and experiments.

scholarly journals Near-field thermophotovoltaics for efficient heat to electricity conversion at high power density

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Rohith Mittapally ◽  
Byungjun Lee ◽  
Linxiao Zhu ◽  
Amin Reihani ◽  
Ju Won Lim ◽  
...  
Keyword(s):  
Power Density ◽  
High Power ◽  
High Efficiency ◽  
Near Field ◽  
Electrical Power ◽  
Photovoltaic Cells ◽  
High Power Density ◽  
Pv Cell ◽  
Electrical Power Output ◽  
Power Densities

AbstractThermophotovoltaic approaches that take advantage of near-field evanescent modes are being actively explored due to their potential for high-power density and high-efficiency energy conversion. However, progress towards functional near-field thermophotovoltaic devices has been limited by challenges in creating thermally robust planar emitters and photovoltaic cells designed for near-field thermal radiation. Here, we demonstrate record power densities of ~5 kW/m2 at an efficiency of 6.8%, where the efficiency of the system is defined as the ratio of the electrical power output of the PV cell to the radiative heat transfer from the emitter to the PV cell. This was accomplished by developing novel emitter devices that can sustain temperatures as high as 1270 K and positioning them into the near-field (<100 nm) of custom-fabricated InGaAs-based thin film photovoltaic cells. In addition to demonstrating efficient heat-to-electricity conversion at high power density, we report the performance of thermophotovoltaic devices across a range of emitter temperatures (~800 K–1270 K) and gap sizes (70 nm–7 µm). The methods and insights achieved in this work represent a critical step towards understanding the fundamental principles of harvesting thermal energy in the near-field.

High-Power-Density High-Efficiency Bottom-Emitting Vertical-Cavity Surface-Emitting Laser Array

2011 ◽  
Vol 4 (5) ◽  
pp. 052104 ◽  
Author(s):  
Di Liu ◽  
Yongqiang Ning ◽  
Yugang Zeng ◽  
Li Qin ◽  
Yun Liu ◽  
...  
Keyword(s):  
Power Density ◽  
High Power ◽  
High Efficiency ◽  
Cavity Surface ◽  
High Power Density ◽  
Laser Array ◽  
Vertical Cavity Surface ◽  
Surface Emitting Laser ◽  
Vertical Cavity

scholarly journals Gust Mitigation of Micro Air Vehicles Using Passive Articulated Wings

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Adetunji Oduyela ◽  
Nathan Slegers
Keyword(s):  
Experimental Validation ◽  
Micro Air Vehicles ◽  
Flight Test ◽  
Analytical Investigation ◽  
Micro Air Vehicle ◽  
Gust Alleviation ◽  
Air Vehicle ◽  
Lifting Surfaces ◽  
Gust Mitigation ◽  
Air Vehicles

Birds and insects naturally use passive flexing of their wings to augment their stability in uncertain aerodynamic environments. In a similar manner, micro air vehicle designers have been investigating using wing articulation to take advantage of this phenomenon. The result is a class of articulated micro air vehicles where artificial passive joints are designed into the lifting surfaces. In order to analyze how passive articulation affects performance of micro air vehicles in gusty environments, an efficient 8 degree-of-freedom model is developed. Experimental validation of the proposed mathematical model was accomplished using flight test data of an articulated micro air vehicle obtained from a high resolution indoor tracking facility. Analytical investigation of the gust alleviation properties of the articulated micro air vehicle model was carried out using simulations with varying crosswind gust magnitudes. Simulations show that passive articulation in micro air vehicles can increase their robustness to gusts within a range of joint compliance. It is also shown that if articulation joints are made too compliant that gust mitigation performance is degraded when compared to a rigid system.

Design and Analysis Software for Propellers

2013 ◽  
Author(s):  
Rajeevalochanam Prathapanayaka ◽  
Nanjundaiah Vinod Kumar ◽  
Krishnamurthy Settisara Janney ◽  
Hari Krishna Nagishetty
Keyword(s):  
Performance Analysis ◽  
Reynolds Numbers ◽  
Performance Comparison ◽  
High Lift ◽  
Low Reynolds Numbers ◽  
Propeller Design ◽  
Air Vehicle ◽  
Loss Method ◽  
Propeller Performance ◽  
Air Vehicles

Recent interest in the field of micro and nano scale air vehicles attracted the attention of many researchers all over the world. The challenge associated with these classes of vehicles is to develop efficient miniaturized components. There are different types of micro and nano air vehicles out of which fixed wing micro air vehicle is one of them. Propulsion system for most of the fixed wing MAVs is propeller driven by an electric motor powered by a battery. The endurance of the MAV mainly depends on the performance of these two components. Hence there is a scope to improve the performance of the propeller and motor. Efficient propeller design and its performance analysis are an iterative process and time consuming. In the present study, to ease the process of propeller design and analysis NALPROPELLER code has been developed using MATLAB. This code is based on minimum induced loss theory presented by E.E.Larrabee to generate planform, blade element momentum theory along with Prandtl hub-tip loss model for overall performance analysis and the performance plots could be viewed in the GUI windows. The code consists of three modules namely single airfoil design, multi airfoil design and analysis module. This code is compared with one of the propeller design and analysis code available in the internet JavaProp by Martin Hepperle, which is also based on minimum induced loss method. From literature Eppler 193 airfoil show high lift to drag ratios at low Reynolds numbers [16]. Eppler-193 airfoil is used in the evaluation of propeller performance. A four inch diameter, two bladed, fixed pitch propeller is designed and analysed using this code. The design is compared with one of the design software JavaProp available online as an open source. A poly urethane casting propeller is fabricated based on the design. The performance comparison of the NALPROPELLER code, JavaProp and 3D CFD analysis is presented and discussed.

From falling to flying: the path to powered flight of a robotic samara nano air vehicle

2010 ◽  
Vol 5 (4) ◽  
pp. 045009 ◽  
Author(s):  
Evan R Ulrich ◽  
Darryll J Pines ◽  
J Sean Humbert
Keyword(s):  
Air Vehicle ◽  
Nano Air Vehicle
Sign in / Sign up

Export Citation Format

Share Document