Xiaohua Zhu^1,*, Li Zeng¹, Bo Li¹

CMES-Computer Modeling in Engineering & Sciences, Vol.121, No.2, pp. 631-660, 2019, DOI:10.32604/cmes.2019.06755

Abstract The complicated geological conditions will bring great challenges to the drillstring of horizontal wells for the reason that the increase of the well depth in SichuanChongqing region. Since drillstring failure and friction during drilling are generally caused by drillstring vibration, great importance must be attached to computer simulation methods for the prediction of drillstring vibration. A finite element model considering axial, lateral and torsional vibration is established. In order to verify the established numerical model, an indoor experimental device based on the similarity principle was established. The vibration characteristics of three shale gas horizontal wells… More >

Witold Elsner^1,*, Artur Dróżdż¹, Paweł Niegodajew¹

The International Conference on Computational & Experimental Engineering and Sciences, Vol.21, No.2, pp. 41-41, 2019, DOI:10.32604/icces.2019.05114

Abstract Estimation of the wall skin friction in a turbulent boundary layer (TBL) is always challenging due to the large gradient of mean velocity in the near-wall region and requires precise measurements of mean velocity in viscous sublayer. This problem becomes even more serious for a flow with a strong positive pressure gradient where the low velocity closes the wall occurs. Hence, choosing an appropriate measuring technique for the wall skin friction measurement is an important issue. Most commonly used for this purpose is hot-wire technique, where determination of mean velocity gradient is strongly dependent on… More >

Morgan Chabannes^1,2,*, Frédéric Becquart^1,2, Nor-Edine Abriak^1,2

Journal of Renewable Materials, Vol.7, No.9, pp. 855-863, 2019, DOI:10.32604/jrm.2019.06779

Abstract The return to old building methods by mixing crop by-products with mineral binders is arousing great interest in Europe since about 25 years. The use of these bio-aggregates based materials for the design of building envelopes is a valuable opportunity to deal with increasingly demanding thermal regulations. In addition, the regulatory framework is moving towards reducing the overall car-bon footprint of new buildings. Some traditional and historic buildings are based on timber framing with earth-straw as infill material for instance. Hemp concrete is a bio-based material that can be manually tamped in timber stud walls… More >

Wei Guo^1,2, Chen Zeng^1,2, Hongye Gou^3,*, Yao Hu^1,2, Hengchao Xu⁴, Longlong Guo^1,2

CMES-Computer Modeling in Engineering & Sciences, Vol.120, No.3, pp. 491-515, 2019, DOI:10.32604/cmes.2019.06162

Abstract CRTS-II slab ballastless track on bridge is a unique system in China high speed railway. The application of longitudinal continuous track system has obviously changed dynamic characteristics of bridge structure. The bridge system and CRTS-II track system form a complex nonlinear system. To investigate the seismic response of high speed railway (HSR) simply supported bridge-track system, nonlinear models of three-span simply supported bridge with piers of different height and CRTS-II slab ballastless track system are established. By seismic analysis, it is found that shear alveolar in CRTS-II track system is more prone to be damaged… More >

Amnart Boonloi^a, Withada Jedsadaratanachai^b,*

Frontiers in Heat and Mass Transfer, Vol.10, pp. 1-19, 2018, DOI:10.5098/hmt.10.6

Abstract Convective heat transfer, pressure loss and thermal performance in a heat exchanger tube inserted with the modified V-shaped baffle are investigated numerically. The influences of the flow attack angle (α = 20o , 30o and 45o ), baffle height in term of blockage ratio (b/D = BR = 0.05, 0.10, 0.15, 0.20 and 0.25) and arrangement (The V-tip pointing downstream is called “V-Downstream”, while the V-tip pointing upstream is named “V-Upstream”.) on heat transfer and friction loss are presented for the Reynolds number in range 100 – 1200 (laminar region). The numerical study (finite volume… More >

Yashwant Singh^a , Rajesh Maithani^b , Sunil Kumar^a , Ehsan Gholamalizadeh^c , Anil Kumar^a,d,*

Frontiers in Heat and Mass Transfer, Vol.11, pp. 1-16, 2018, DOI:10.5098/hmt.11.33

Abstract Nanofluids play important roles in the heat transfer and flow characteristics in ribbed square channels. Systematic experiments are conducted to measure heat transfer enhancement and TiO₂-H₂O based nanofluid flow characteristics on a protruded with combined V-type ribbed square channel. Reynolds number studied in the channel range from 4000-18000. Investigational parameters of square channel contain, volume fraction range of 1.0- 4.0%, particle diameter range of 30nm-45nm, relative protruded rib height range of 0.10-0.25, ratio of protruded height to print diameter range of 0.8- 2.0, relative protruded rib pitch ratio range of 2.0-3.5 and angle of attack of… More >

Ralph Eismann^a,† , Robert Adams^b

Frontiers in Heat and Mass Transfer, Vol.11, pp. 1-7, 2018, DOI:10.5098/hmt.11.4

Abstract Convergence of numerical schemes for pipe network analysis requires continuous modelling of pressure losses in the transition region between laminar and turbulent regions. Several existing correlations for the friction factor of straight pipes and helical tubes are presented. Based on these correlations a new explicit correlation for helical tubes with arbitrary surface roughness is derived. The friction factor is expressed as a continuous function of the Reynolds number covering laminar, transitional, and turbulent flow regions. Potential sources of error are also discussed, including the effects of tube deformation caused by the bending process. More >

Kyung Sung Kim¹, Moo-Hyun Kim^2,*, Hakun Jang³, Hee Chen Cho⁴

CMES-Computer Modeling in Engineering & Sciences, Vol.116, No.1, pp. 11-29, 2018, DOI:10.31614/cmes.2018.00199

Abstract A new MPS (Moving Particle Semi-implicit) method is developed to simulate the behaviors and interactions of multiple fine solid particles as a continuum. As fluid particles are affected by viscosity, so solid particles are affected by friction. The solid particle dynamics for landslides, dumping, and gravity sorting etc. which can be difficult to simulate using conventional MPS methods, are modeled in this paper using the developed multi-solid-particle MPS method that benefits from drawing comparisons with the corresponding fluid particle behaviors. The present MPS results for dumping solid particles are verified against the corresponding DEM (Discrete… More >

Sanjay K. Sharma¹, V. R. Kalamkar^{1, *}

CMES-Computer Modeling in Engineering & Sciences, Vol.114, No.3, pp. 295-319, 2018, DOI:10.3970/cmes.2018.114.295

Abstract The three-dimensional numerical investigation of an incompressible flow through rib roughened solar air heater is carried out. A combination of thin transverse and truncated ribs is attached on the absorber plate to study its effect on the heat transfer and friction factor. The parameters in the form of Reynolds number (Re) of 4000-16000, relative roughness pitch (P/e) of 8-18 and relative roughness height (e/Dh) of 0.0366-0.055 is considered for the analysis. The CFD code ANSYS FLUENT is used to solve the governing equations of turbulent flow. The RNG k–ε turbulence model is used to solve More >

Solenne Mondésert-Deveraux^{1, *}, Rachele Allena², Denis Aubry¹

Molecular & Cellular Biomechanics, Vol.15, No.3, pp. 155-176, 2018, DOI:10.3970/mcb.2018.03053

Abstract Cell migration is the cornerstone of many biological phenomena such as cancer metastasis, immune response or organogenesis. Adhesion-based motility is the most renown and examined motility mode, but in an adhesion-free confined environment or simply to achieve a higher migration speed, cells can adopt a very interesting bleb-based migration mode called “chimneying”. This mode rests on the sharp synchronization between the active contraction of the cells uropod and the passive friction force between the cell and the confining surface. In this paper, we propose a one dimensional poroelastic model of chimneying which considers the active… More >