Lihua Wang^{1, *}, Wenjing Ye¹, Yueting Zhou¹

CMES-Computer Modeling in Engineering & Sciences, Vol.122, No.3, pp. 889-906, 2020, DOI:10.32604/cmes.2020.09013

Abstract The lift force was reported not to be high enough to support the dragonfly’s weight during flight in some conventional investigations, and higher lift force is required for its takeoff. In this study, by employing a thin plate model, impact effect is investigated for the wing deformation in dragonfly flapping during takeoff. The static displacement is formulated to compare with the dynamical displacement caused by impact. The governing equation of motion for the impact dynamics of a dragonfly wing is derived based on Newton’s second law. Separation of variables technique and assumed modes method are introduced to solve the resulting… More >

Bonvissuto GL¹, CA Busso^2,*

Phyton-International Journal of Experimental Botany, Vol.75, pp. 55-70, 2006, DOI:10.32604/phyton.2006.75.055

Abstract This study was conducted in the Monte Austral Neuquino (MAN), Provincia de Neuquén, Argentina (39°20’ S; 69°19’ W). Vegetation is distributed at the site as vegetation patches. There are two contrasting sites on the soil of these patches: location 1, under the canopy of major perennial grasses and shrubs, and location 2, which includes the vegetation uncovered interspaces between the patches. The hypothesis of this work was that hydraulic lift is greater under than between the vegetation patches. Thermocouple psychrometers were placed under the shrubs and in the interspaces in each of two vegetation patches, and water potential measurements were… More >

Yi Luo^1,*, Erxiu Shi², Yin Feng², Boyun Guo², Liehui Zhang¹

CMES-Computer Modeling in Engineering & Sciences, Vol.121, No.1, pp. 105-122, 2019, DOI:10.32604/cmes.2019.06500

Abstract Development of unconventional tight oil and gas reservoirs such as shale pays presents a huge challenge to the petroleum industry due to the naturally low permeability of shale formations and thus low productivity of oil and gas wells. Shale formations are also vulnerable to the contamination of the water in the drilling and completion fluids, which further reduces reservoir permeability. Although gas-drilling (drilling with gas) has been used to address the issue, several problems such as formation water influx, wellbore collapse, excessive gas volume requirement and hole cleaning in horizontal drilling, still hinder its application. A new technique called gas-lift… More >

Ji Won Yoon¹, Tae Won Park², Kab Jin Jun³, Soo Ho Lee³, Sung Pil Jung³

The International Conference on Computational & Experimental Engineering and Sciences, Vol.11, No.3, pp. 73-74, 2009, DOI:10.3970/icces.2009.011.073

Abstract Industrial vehicles like forklifts are used in many areas, such as the heavy industries, shipbuilding, and manufacturing industries. Recently, the rise in the oil prices and stricter environmental regulations have created the need for new technologies for industrial vehicles. Presently, the performance of the power train has reached its limit and cannot be further improved without increasing cost, weight and volume. Therefore, a system based on a new paradigm is needed. To achieve this goal, the structure of the power transfer system needs to be revolutionized. First, weight and size need to be reduced. In addition, the number of gears… More >

Wang Yang^1,2, Juanjuan Li¹, Jian Yang^1,3, Lin Wei⁴

CMES-Computer Modeling in Engineering & Sciences, Vol.104, No.6, pp. 471-491, 2015, DOI:10.3970/cmes.2015.104.471

Abstract Harvesting is the most difficult and costly operation in cassava production. Currently, most cassava harvest still depends on manual tools. Effective mechanized harvesters are necessary to improve harvesting quality and reduce production cost. Therefore, it is very important to figure out key information for designing an effective tuber lifting system used in bionic “dig-pull” harvesters. A numerical simulation model of human-stem-tuber-soil system was developed to carry out numerical simulation of manually pulling tuber. Coupling algorithm of Lagrange and smoothed particle hydrodynamics (SPH) was used in the model. Lifting mechanism of experienced farmer was studied at a micro level. Influence of… More >

Y.M. Wang^1,2, Q. Wu¹

CMES-Computer Modeling in Engineering & Sciences, Vol.93, No.1, pp. 17-45, 2013, DOI:10.3970/cmes.2013.093.017

Abstract A new kind of operator-orthogonal wavelet-based element is constructed based on the lifting scheme for adaptive analysis of thin plate bending problems. The operators of rectangular and skew thin plate bending problems and the sufficient condition for the operator-orthogonality of multilevel stiffness matrix are derived in the multiresolution finite element space. A new type of operator-orthogonal wavelets for thin plate bending problems is custom designed with high vanishing moments to be orthogonal with the scaling functions with respect to the operators of the problems, which ensures the independent solution of the problems in each scale. An adaptive operator-orthogonal wavelet method… More >

Jun Li¹, Shunji Yang¹, Boyun Guo^1,2, Yin Feng², Gonghui Liu^1,3

CMES-Computer Modeling in Engineering & Sciences, Vol.89, No.2, pp. 79-96, 2012, DOI:10.3970/cmes.2012.089.079

Abstract In the process of gas drilling, the mechanism of transport of the cuttings up the annulus is significant, because it controls the minimum amount of volume of the required gas, the cost of cleaning the borehole, the stability of the borewell and the drill pipe erosion, etc. However, current studies in this area are only limited to theoretical discussions. The reason why drill cuttings are of very fine sizes , in air drilling, is believed to be due to the repeated crushing action of drill bit at the bottom of the hole, and the collision between cuttings themselves and the… More >

G. Trapani¹, T. Kipouros¹, A. M. Savill¹

CMES-Computer Modeling in Engineering & Sciences, Vol.88, No.2, pp. 107-140, 2012, DOI:10.3970/cmes.2012.088.107

Abstract This paper presents the development and the application of a multi-objective optimization framework for the design of two-dimensional multi-element high-lift airfoils. An innovative and efficient optimization algorithm, namely Multi-Objective Tabu Search (MOTS), has been selected as core of the framework. The flow-field around the multi-element configuration is simulated using the commercial computational fluid dynamics (cfd) suite Ansys cfx. Elements shape and deployment settings have been considered as design variables in the optimization of the Garteur A310 airfoil, as presented here. A validation and verification process of the cfd simulation for the Garteur airfoil is performed using available wind tunnel data.… More >