HIGH EFFICIENCY STRUCTURAL FLOWTHROUGH ROTOR WITH ACTIVE FLAP CONTROL: VOLUME ONE: PRELIMINARY DESIGN REPORT

Рассматривается ускорение параллельных гидродинамических расчетов на кластерах с CPU- и GPU-узлами. Для тестирования используется собственный CFD-код SigmaFlow, портированный для расчетов на графических ускорителях с помощью технологии CUDA. Алгоритм моделирования течения несжимаемой жидкости основан на SIMPLE-подобной процедуре и дискретизации с помощью метода контрольного объема на неструктурированных сетках из тексаэдральных ячеек. Сравнение скорости расчета показывает высокую производительность графических ускорителей нового поколения в GPGPU-расчетах. Speedup of parallel hydrodynamic calculations on clusters with CPUs and GPUs is considered. The CFD SigmaFlow code developed by the authors and ported for GPU by means of CUDA is used in test calculations. The incompressible flow simulation is based on a SIMPLE-like procedure and on a discretization by the control volume method on unstructured hexahedral meshes. The performance evaluation shows a high efficiency of the new generation of GPUs for GPGPU calculations.

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The jumping mechanism of flea beetles (Coleoptera, Chrysomelidae, Alticini), its application to bionics and preliminary design for a robotic jumping leg

ZooKeys ◽

10.3897/zookeys.915.38348 ◽

2020 ◽

Vol 915 ◽

pp. 87-105

Author(s):

Yongying Ruan ◽

Alexander S. Konstantinov ◽

Guanya Shi ◽

Yi Tao ◽

You Li ◽

...

Keyword(s):

High Speed ◽

High Efficiency ◽

Flea Beetle ◽

Hind Femur ◽

Feedback Mechanism ◽

Preliminary Design ◽

Micro Ct ◽

Flea Beetles ◽

Small Structure ◽

Positive Feedback Mechanism

Flea beetles (Coleoptera, Chrysomelidae, Galerucinae, Alticini) are a hyperdiverse group of organisms with approximately 9900 species worldwide. In addition to walking as most insects do, nearly all the species of flea beetles have an ability to jump and this ability is commonly understood as one of the key adaptations responsible for its diversity. Our investigation of flea beetle jumping is based on high-speed filming, micro-CT scans and 3D reconstructions, and provides a mechanical description of the jump. We reveal that the flea beetle jumping mechanism is a catapult in nature and is enabled by a small structure in the hind femur called an ‘elastic plate’ which powers the explosive jump and protects other structures from potential injury. The explosive catapult jump of flea beetles involves a unique ‘high-efficiency mechanism’ and ‘positive feedback mechanism’. As this catapult mechanism could inspire the design of bionic jumping limbs, we provide a preliminary design for a robotic jumping leg, which could be a resource for the bionics industry.

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Design of High Efficiency Blowers for Future Aerosol Applications

Volume 2: Fora ◽

10.1115/fedsm2009-78234 ◽

2009 ◽

Author(s):

Raman Chadha ◽

Gerald L. Morrison ◽

Andrew R. McFarland

Keyword(s):

Flow Rate ◽

High Efficiency ◽

Static Pressure ◽

Pressure Rise ◽

Electrical Energy ◽

Design Flow ◽

Preliminary Design ◽

Aerosol Sampling ◽

Wall Functions ◽

Low Efficiency

High efficiency air blowers to meet future portable aerosol sampling applications were designed, fabricated, and their performance evaluated. A preliminary blower design based on specific speed was selected, modeled in CFD, and the flow field simulated. This preliminary blower size was scaled in planar and axial directions, at different rpm values, to set the Best Efficiency Point (BEP) at a flow rate of 100 L/min (1.67×10−3 m3/s @ room conditions) and a pressure rise of 1000 Pa (4″ WC). Characteristic curves for static pressure rise versus air flow rate through the impeller were generated. Experimentally measured motor/blower combination efficiency (ηEXP) for the preliminary design was around 10%. The low value was attributed to the low efficiency of the D.C. motor used (Chadha, 2005). CFD simulations using the κ–ε turbulent model and standard wall function (non-equilibrium wall functions) approach overpredicted the head values. Enhanced wall treatment under-predicted the head rise but provided better agreement with experimental results. The static pressure rise across the final blower is 1021 Pa at the design flow rate of 100 L/min. Efficiency value based on measured static pressure rise value and the electrical energy input to the motor (ηEXP) is 26.5%, a 160% improvement over the preliminary design.

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Preliminary Design and Off-Design Analysis of a Radial Outflow Turbine for Organic Rankine Cycles

Energies ◽

10.3390/en13082118 ◽

2020 ◽

Vol 13 (8) ◽

pp. 2118 ◽

Cited By ~ 1

Author(s):

Jun-Seong Kim ◽

Do-Yeop Kim

Keyword(s):

High Efficiency ◽

Velocity Ratio ◽

Design Procedure ◽

Design Analysis ◽

Operating Conditions ◽

Flow Coefficient ◽

Fine Tuning ◽

Preliminary Design ◽

Organic Rankine Cycles ◽

Radial Outflow

Recently, the advantages of radial outflow turbines have been outstanding in various operating conditions of the organic Rankine cycle. However, there are only a few studies of such turbines, and information on the design procedure is insufficient. The main purpose of this study is to provide more detailed information on the design methodology of the turbine. In this paper, a preliminary design program of a radial outflow turbine for organic Rankine cycles was developed. The program determines the main specifications of the turbine through iterative calculations using the enthalpy loss model and deviation angle model. For reliability evaluation of the developed algorithm, a 400.0 kW turbine for R143a was designed. The designed turbine was validated through computational fluid dynamics. As a result, the accuracy of the program was about 95% based on the turbine power, which shows that it is reliable. In addition, the turbine target performance could be achieved by fine-tuning the blade angle of the nozzle exit. In addition, performance evaluation of the turbine against off-design conditions was performed. Ranges of velocity ratio, loading coefficient, and flow coefficient that can expect high efficiency were proposed through the off-design analysis of the turbine.

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