Shiwei Qin, Zili Dai^*

CMES-Computer Modeling in Engineering & Sciences, Vol.136, No.3, pp. 3157-3172, 2023, DOI:10.32604/cmes.2023.026874

Abstract High-resolution underwater digital elevation models (DEMs) are important for water and soil conservation, hydrological analysis, and river channel dredging. In this work, the underwater topography of the Panjing River in Shanghai, China, was measured by an unmanned surface vessel. Five different interpolation methods were used to generate the underwater DEM and their precision and applicability for different underwater landforms were analyzed through cross-validation. The results showed that there was a positive correlation between the interpolation error and the terrain surface roughness. The five interpolation methods were all appropriate for the survey area, but their accuracy varied with different surface roughness.… More >

Zhenguo Liu^1,2, Shuchen Li^1,3, Richeng Liu^3,*, Changzhou Zheng²

CMES-Computer Modeling in Engineering & Sciences, Vol.136, No.2, pp. 1427-1440, 2023, DOI:10.32604/cmes.2023.025414

Abstract The nonlinear flow properties of Newtonian fluids through crossed fractures are estimated by considering the influences of length, aperture, and surface roughness of fractures. A total of 252 computational runs are performed by creating 36 computational domains, in which the Navier-Stokes equations are solved. The results show that the nonlinear relationship between flow rate and hydraulic gradient follows Forchheimer’s law–based equation. When the hydraulic gradient is small (i.e., 10⁻⁶), the streamlines are parallel to the fracture walls, indicating a linear streamline distribution. When the hydraulic gradient is large (i.e., 10⁰), the streamlines are disturbed by a certain number of eddies,… More >

Abdul Wahab Hashmi¹, Harlal Singh Mali¹, Anoj Meena¹, Mohammad Farukh Hashmi², Neeraj Dhanraj Bokde^3,4,*

CMES-Computer Modeling in Engineering & Sciences, Vol.135, No.2, pp. 917-1005, 2023, DOI:10.32604/cmes.2023.021223

Abstract Computer vision provides image-based solutions to inspect and investigate the quality of the surface to be measured. For any components to execute their intended functions and operations, surface quality is considered equally significant to dimensional quality. Surface Roughness (Ra) is a widely recognized measure to evaluate and investigate the surface quality of machined parts. Various conventional methods and approaches to measure the surface roughness are not feasible and appropriate in industries claiming 100% inspection and examination because of the time and efforts involved in performing the measurement. However, Machine vision has emerged as the innovative approach to executing the surface… More >

Yuhang He¹, Rongzhuo Zhang¹, Sarah Mohrmann², Zheng Wang^1,*, Jiujin Fang³

Journal of Renewable Materials, Vol.10, No.12, pp. 3303-3311, 2022, DOI:10.32604/jrm.2022.020681

Abstract In order to explore the characteristics of the three-dimensional surface morphology of sawn timber, a threedimensional wood surface morphology tester based on the scanning probe method and the principle of atomic force microscope was used to test the three-dimensional surface morphology of three kinds of sawn timber and calculate its surface roughness. This study also analyzed the reasonable plan for the value of wood surface roughness and the advantages of the three-dimensional shape tester, as well as the influence of tree species, three sections, air-dry density and other factors on the surface roughness of the specimen after mechanical processing. The… More >

A. F. Mohamed^1,2, J. Abu Alsoud¹, Mujahed Al-Dhaifallah^3,*, Hegazy Rezk^4,5, Mohamed K. Hassan^1,6

CMC-Computers, Materials & Continua, Vol.71, No.1, pp. 71-83, 2022, DOI:10.32604/cmc.2022.019257

Abstract In power plants, flue gases can cause severe corrosion damage in metallic parts such as flue ducts, heat exchangers, and boilers. Coating is an effective technique to prevent this damage. A robust fuzzy model of the surface roughness (R_a and R_z) of flue gas ducts coated by protective composite coating from epoxy and nanoparticles was constructed based on the experimental dataset. The proposed model consists of four nanoparticles (ZnO, ZrO₂, SiO₂, and NiO) with 2%, 4%, 6%, and 8%, respectively. Response surface methodology (RSM) was used to optimize the process parameters and identify the optimal conditions for minimum surface roughness… More >

Liu Cao^*

CMES-Computer Modeling in Engineering & Sciences, Vol.126, No.1, pp. 5-23, 2021, DOI:10.32604/cmes.2021.014693

Abstract As a typical laser additive manufacturing technology, laser powder bed fusion (LPBF) has achieved demonstration applications in aerospace, biomedical and other fields. However, how to select process parameters quickly and reasonably is still the main concern of LPBF production. In order to quantitatively analyze the inuence of different process parameters (laser power, scanning speed, hatch space and layer thickness) on the LPBF process, the multi-layer and multi-path forming process of LPBF was predicted based on the open-source discrete element method framework Yade and the open-source finite volume method framework OpenFOAM. Based on the design of experiments method, a four-factor three-level… More >

Haitao Yue¹, Chenguang Guo^1,*, Qiang Li¹, Lijuan Zhao¹, Guangbo Hao²

CMES-Computer Modeling in Engineering & Sciences, Vol.124, No.3, pp. 937-952, 2020, DOI:10.32604/cmes.2020.010565

Abstract To improve the milling surface quality of the Al-Li alloy thin-wall workpieces and reduce the cutting energy consumption. Experimental research on the milling processing of AA2195 Al-Li alloy thin-wall workpieces based on Response Surface Methodology was carried out. The single factor and interaction of milling parameters on surface roughness and specific cutting energy were analyzed, and the multi-objective optimization model was constructed. The Multiobjective Particle Swarm Optimization algorithm introducing the Chaos Local Search algorithm and the adaptive inertial weight was applied to determine the optimal combination of milling parameters. It was observed that surface roughness was mainly influenced by feed… More >

Hui Lu, Xinyue Duan, Minghai Xu^*, Liang Gong, Bin Ding

CMES-Computer Modeling in Engineering & Sciences, Vol.123, No.3, pp. 1193-1204, 2020, DOI:10.32604/cmes.2020.08989

Abstract In micro-manufacturing, roughness is unavoidable due to the tolerance of micro-machining methods. Roughness in microchannel could have a significant influence on flow and heat transfer since the size of microchannel is very small. In our work, roughness is modeled as a superposition of waves. A simple Fourier series method is proposed to construct the rough surface. With this method, roughness is constructed on the bottom of the rectangular microchannel which has a hydraulic diameter of 0.5 mm. Two important parameters during roughness construction, triangulate size and correlation length are studied under the same relative roughness 1%. Results show that flow… More >

F. Dierich¹, P.A. Nikrityuk¹

CMES-Computer Modeling in Engineering & Sciences, Vol.64, No.3, pp. 251-266, 2010, DOI:10.3970/cmes.2010.064.251

Abstract This work presents a numerical investigation of the influence of the roughness of a cylindrical particle on the drag coefficient and the Nusselt number at low Reynolds numbers up to 40. The heated cylindrical particle is placed horizontally in a uniform flow. Immersed boundary method (IBM) with a continuous forcing on a fixed Cartesian grid is used. The governing equations are the Navier Stokes equation and the conservation of energy. A finite-volume based discretization and the SIMPLE algorithm with collocated-variables and Rie-Chow stabilization were used to solve the set of equations. Numerical simulations showed that the impact of the roughness… More >

N. Liu,¹,W. Gao ¹, C.M. Song¹, N. Zhang²

CMES-Computer Modeling in Engineering & Sciences, Vol.72, No.2, pp. 79-102, 2011, DOI:10.3970/cmes.2011.072.079

Abstract This paper presents the probabilistic dynamic analysis of vehicle-bridge interaction systems. The bridge's and vehicle's parameters are considered as random variables as well as the road surface roughness is modeled as random process. A two-degree-of-freedom spring-mass system is used to represent a moving vehicle and the bridge is modeled as an Euler-Bernoulli beam. From the equation of motion for the vehicle-bridge coupling system, the expressions for mean value and standard deviation of bridge response are developed by using the random variable's functional moment method. The effects of the individual system parameters and the road surface roughness on the bridge response… More >