This paper studies the trajectory tracking problem of flapping-wing micro aerial vehicles (FWMAVs) in longitudinal plane. First all, kinematics and dynamics FWMAV are established, wherein aerodynamic force torque generated by flapping wings tail wing explicitly formulated with respect to frequency degree inclination. To achieve autonomous tracking, an adaptive control scheme is proposed under hierarchical framework. Specifically, a bounded position controller hyperbolic tangent functions...

The study of reduced-order models (ROMs) for flow fields is crucial in control, prediction, and digital twin applications. ROM provides a powerful tool reducing the computational cost simulating phenomena, making it indispensable aforementioned fields. Although various ROMs have been recently proposed, most are limited to simple structures with prominent features. applicability accuracy existing methods remain more complex scenarios. Therefore, we propose novel data-driven framework. This...

In this work, a multiobjective aerodynamic optimization of high-speed train head was performed to improve the performance running on an embankment under crosswinds. Seven design variables were selected control five regions head. The total drag force, lift and side force coach set as objectives. optimal Latin hypercube sampling method used obtain values sample points. deformed using free-form deformation approach through which mesh morphing without remodeling re-meshing. Then, performances...

A broadband noise source model based on Lighthill’s acoustic theory was used to perform numerical simulations of the aerodynamic sources for a high-speed train. The near-field unsteady flow around train analysed delayed detached-eddy simulation (DDES) using finite volume method with high-order difference schemes. far-field from predicted computational fluid dynamics (CFD)/Ffowcs Williams-Hawkings (FW-H) analogy. An analysis reduction methods main performed. full-scale train, including three...

Horizontal axis wind turbine (hereafter HAWT) is the common equipment in generator systems recent years. The paper relates to numerical simulation of unsteady airflow around a HAWT type Phase VI with emphasis on power output. rotor diameter 10-m and rotating speed 72 rpm. was undertaken Computational Fluid Dynamics (CFD) software FLUENT 6.2 using sliding meshes controlled by user-defined functions (UDF). Entire mesh node number about 1.8 million it generated GAMBIT 2.2 achieve better...

摘要:

Based on the modeling of bird-like flapping-wing micro aerial vehicle (FWMAV), this paper makes detailed analysis trajectory generation FWMAV, and gives parameter calculation under different constraint conditions. Firstly, kinematics dynamics model FWMAV that considered aerodynamic force caused by flapping wings tail wing are built. After that, a smooth incorporating with initial constraints is proposed. The algorithm can satisfy characteristic which make achieve to target circular smoothly...

In order to improve the aerodynamic performance of pantograph fairing a high-speed train, an shape optimization design approach was proposed based on multi-objective genetic algorithm and theory computational fluid dynamics (CFD). The drag force acoustic power level were set be objectives. A three-dimensional (3D) parametric model established 4 variables extracted. script files software CATIA STAR-CCM+ integrated into ISIGHT, then automatic deformation calculation train aerodynamics could...

Based on the ancient method of nine-steaming and nine-sun-curing,the chemical composition changes quality profiles in different processes Polygoni Multiflori Radix were studied. Their contents stilbene glycoside,anthraquinones polysaccharides determined by nine-sun-curing with black bean juice pharmacopoeia method. HPLC fingerprints established,and orthogonal partial least squares-discriminant analysis( OPLS-DA) was performed processed products using SIMCA 14. 1 software to evaluate...

The engine cooling water jacket has a major impact on the efficiency of engine. In this paper flow in six-cylinder four stroke water-cooled diesel was studied with commercial software STAR CCM+. Results simulation reveals that velocity little effect field distributions. Dead zone cylinder head appeared far away from inlet flow. But it could be avoided or improved effectively by arranging and outlet at opposite side jacket. Further study suggests good distribution can achieved near entrance...

On the basis of overall structure design and aerodynamic calculation annular low-speed wind tunnel, this paper uses CFD numerical simulation technique to study influence contraction curve form, ratio open/closed loop form test section on flow field quality tunnel section, then gives three-dimensional geometric model results. It is found that best can be obtained by using bicubic curve, 10.24 closed under same fan condition. The modeling method adopted in paper, which obtain more accurate...

Flapping-wing flying robots, as a newly emerging research hotspot, have attracted more and researchers' attention. Compared with traditional aircraft, flapping-wing robots the characteristics of high flight efficiency, good concealment, wide range application prospects. As an important power mechanism wing is very important. In this paper, we design structure that can realize active bending wings, which well imitate pattern wings birds in natural process. At same time, wind tunnel test was...