Zisheng Yang¹, Wendong Li¹, Xuelei Cheng^1,2,*, Ran Hai¹, Shunqun Li³

FDMP-Fluid Dynamics & Materials Processing, Vol.19, No.8, pp. 2119-2130, 2023, DOI:10.32604/fdmp.2023.025444 - 04 April 2023

Abstract Sixteen groups of comprehensive tests have been conducted to investigate the modifications in the physical properties of a weak expansive soil due to the addition of a cement jute fiber. The tests have been conducted to analyze the liquid plastic limit, the particle distribution and the free expansion rate. The results show that: (1) With an increase in the cement-jute fiber content, the free expansion rate of the modified expansive soil gradually decreases, however, such a rate rebounds when the fiber content exceeds 0.5% and the cement content exceeds 6%. (2) With an increase in… More >

Kefan Yang^1,*, Youmin Wang¹, Kexun Fu¹, Jiaqi Chen²

FDMP-Fluid Dynamics & Materials Processing, Vol.19, No.5, pp. 1317-1338, 2023, DOI:10.32604/fdmp.2023.024265 - 30 November 2022

Abstract The design of hydro-bulge molds, able to provide hollow parts with special-shaped cross-sections, is still a pretty complicated task (especially for what concerns the design of the related hydraulic system and its “synchronization”). In the present work, this task is addressed through the introduction of a new type of overhead cylinder hydraulic synchronization system, able to correct automatically any deviation from the optimal process. Using the AMESim software, the displacement synchronization curve of the piston rods of the two cylinders is obtained and it is verified that the system is able to implement an automatic More >

Chunqin Tan¹, Shenglai Guo^2,3,*, Juanjuan Huang⁴

FDMP-Fluid Dynamics & Materials Processing, Vol.19, No.5, pp. 1291-1300, 2023, DOI:10.32604/fdmp.2022.022233 - 30 November 2022

Abstract Generally, the so-called expansion agent is very effective in eliminating all the micro-annuli that exist between the casing and the cement sheath or between the cement sheath and the formation. However, this approach can detrimentally affect the sealing ability of cement sheath if the expansion agent is used in an unreasonable way. For these reasons, in the present work, numerical simulations have been conducted to analyze the effect of elasticity modulus of cement sheath, the elasticity modulus of formation, the expansion rate of cement, the geo-stress on the micro-annulus caused by cement expansion, and the… More >

Fahad Sameer Alshammari¹, Md Fazlul Hoque², Harun-Or-Roshid², Muhammad Nadeem^3,*

CMES-Computer Modeling in Engineering & Sciences, Vol.135, No.3, pp. 2197-2217, 2023, DOI:10.32604/cmes.2023.022301 - 23 November 2022

Abstract We investigate the bounded travelling wave solutions of the Biswas-Arshed model (BAM) including the low group velocity dispersion and excluding the self-phase modulation. We integrate the nonlinear structure of the model to obtain bounded optical solitons which pass through the optical fibers in the non-Kerr media. The bifurcation technique of the dynamical system is used to achieve the parameter bifurcation sets and split the parameter space into various areas which correspond to different phase portraits. All bounded optical solitons and bounded periodic wave solutions are identified and derived conforming to each region of these phase More >

Yingying Li¹, Hang Jiang¹, Lianjie Yu¹, Jianfeng Li^1,2,*

CMES-Computer Modeling in Engineering & Sciences, Vol.134, No.3, pp. 2123-2136, 2023, DOI:10.32604/cmes.2022.021407 - 20 September 2022

Abstract To improve the estimation accuracy, a novel time delay estimation (TDE) method based on the closed-form offset compensation is proposed. Firstly, we use the generalized cross-correlation with phase transform (GCC-PHAT) method to obtain the initial TDE. Secondly, a signal model using normalized cross spectrum is established, and the noise subspace is extracted by eigenvalue decomposition (EVD) of covariance matrix. Using the orthogonal relation between the steering vector and the noise subspace, the first-order Taylor expansion is carried out on the steering vector reconstructed by the initial TDE. Finally, the offsets are compensated via simple least More >

Lixing Zheng^1,*, Weibo Wang², Yiyan Zhang¹, Lingmei Wang³, Wei Lu²

CMES-Computer Modeling in Engineering & Sciences, Vol.133, No.1, pp. 153-170, 2022, DOI:10.32604/cmes.2022.021235 - 18 July 2022

Abstract An improved model to calculate the length of the mixing chamber of the ejector was proposed on the basis of the Fano flow model, and a method to optimize the structures of the mixing chamber and diffuser of the ejector was put forward. The accuracy of the model was verified by comparing the theoretical results calculated using the model to experimental data reported in literature. Variations in the length of the mixing chamber L_m and length of the diffuser L_d with respect to variations in the outlet temperature of the ejector T_c, outlet pressure of the ejector… More >

Abdul Aabid^1,*, Sher Afghan Khan², Muneer Baig¹

FDMP-Fluid Dynamics & Materials Processing, Vol.18, No.6, pp. 1877-1900, 2022, DOI:10.32604/fdmp.2022.021860 - 27 June 2022

Abstract A method based on microjets is implemented to control the flow properties in a convergent-divergent nozzle undergoing a sudden expansion. Three different variants of this active control technique are explored numerically by means of a finite-volume method for compressible fluid flow: with the first one, the control is implemented at the base, with the second at the wall, while the third one may be regarded as a combination of these. When jets are over-expanded, the control is not very effective. However, when a favourable pressure gradient is established in the nozzle, the control becomes effective, More >

Wenzheng Yu¹, Mingxuan Zhu¹, Li Shao¹, Yanbo Shen^2,3,*, Haitao Liu¹, Tianliang Chen¹, Hanxiaoya Zhang⁴

CMC-Computers, Materials & Continua, Vol.73, No.2, pp. 3771-3793, 2022, DOI:10.32604/cmc.2022.027094 - 16 June 2022

Abstract Qinghai Lake Basin area in Gangcha county is selected as the study area in terms of desertification change features in this paper. Based on the remote sensing (RS) and global positioning system (GPS) technologies, the desertification information range from 1989 to 2014 in the study area is extracted. Using the method of the decision tree, the desertification in the research area is been divided into four grades including mild desertification, moderate desertification, severe desertification and serious desertification. The change characteristics of desertification in the study area were analyzed in detail, which showed that the desertification More >

Shenglong Wang^1,*, Jing Yang^1,*, Xiaoyu Ding², Jianpei Zhang¹, Meng Zhao¹

CMES-Computer Modeling in Engineering & Sciences, Vol.132, No.1, pp. 215-249, 2022, DOI:10.32604/cmes.2022.018050 - 02 June 2022

Abstract In recent years, local community detection algorithms have developed rapidly because of their nearly linear computing time and the convenience of obtaining the local information of real-world networks. However, there are still some issues that need to be further studied. First, there is no local community detection algorithm dedicated to detecting a seed-oriented local community, that is, the local community with the seed as the core. The second and third issues are that the quality of local communities detected by the previous local community detection algorithms are largely dependent on the position of the seed… More >

Hongfei Yue¹, Aiguo Fang², Sudong Hua^1,*, Zenghuan Gu³, Yu Jia¹, Cheng Yang⁴

Journal of Renewable Materials, Vol.10, No.8, pp. 2247-2261, 2022, DOI:10.32604/jrm.2022.018901 - 25 April 2022

Abstract A phosphogypsum-based subgrade stabilizer (PBSS) was formulated using industrial by-product phosphogypsum (PG), mixed with slag and calcium-silicon-rich active material (GSR). The active powder (AP) was used to modify PBSS, and PBSS-AP was obtained. PBSS and PBSS-AP were each mixed with 10% silty soil, and cement and lime (CAL: 5% lime + 2% cement) were used as the traditional material for comparative experiments. Samples were cured under standard conditions, and tested for unconfined compressive strength (UCS), water stability, volume expansion, and leachate, to explore the stabilization effect of the three solidified materials on silty soil. The More >