Yuanjun Dai^1,2, Jingan Cui¹, Baohua Li^1,*, Cong Wang¹, Kunju Shi¹

FDMP-Fluid Dynamics & Materials Processing, Vol.20, No.4, pp. 771-786, 2024, DOI:10.32604/fdmp.2023.029584

Abstract A numerical method has been used to analyze the flow field related to a NACA 0015 airfoil with and without a flap and assess the influence of the flap height and angle on the surface pressure coefficient, lift coefficient, and drag coefficient. The numerical results demonstrate that the flap can effectively improve the lift coefficient of the airfoil; however, at small attack angles, its influence is significantly reduced. When the angle of attack exceeds the critical stall angle and the flap height is 1.5% of the chord length, the influence of the flap becomes very evident. As the flap height… More >

Cheng-Kang Guan, James F. Klausner^*, Renwei Mei

Frontiers in Heat and Mass Transfer, Vol.2, No.4, pp. 1-6, 2011, DOI:10.5098/hmt.v2.4.3002

Abstract Pool boiling critical heat flux (CHF) has been measured for pentane, hexane, methanol, FC-72, FC-87, and R113 on a 25.4 mm diameter smooth brass horizontal surface at five different reduced pressures ranging from 0.01to 0.24. The CHF data are compared with various established CHF models as well as the new mechanistic CHF lift-off model recently proposed by the authors. The dependence of CHF on pressure is examined, and it is found that the lift-off model gives a reasonably good prediction of changes in CHF with step changes in the reduced pressure. The R113 and FC-72 boiling curves suggest that a… More >

Peiheng He, Jiye Zhang^*, Lan Zhang, Jiaqi Wang, Yuzhe Ma

CMES-Computer Modeling in Engineering & Sciences, Vol.139, No.1, pp. 937-953, 2024, DOI:10.32604/cmes.2023.043700

Abstract The running stability of high-speed train is largely constrained by the wheel-rail coupling relationship, and the continuous wear between the wheel and rail surfaces will profoundly affect the dynamic performance of the train. In recent years, under the background of increasing train speed, some scientific researchers have proposed a new idea of using the lift force generated by the aerodynamic wings (aero-wing) installed on the roof to reduce the sprung load of the carriage in order to alleviate the wear and tear of the wheel and rail. Based on the bidirectional running characteristics of high-speed train, this paper proposes a… More >

Shiyang Song^1,*, Tongxin Han²

FDMP-Fluid Dynamics & Materials Processing, Vol.20, No.1, pp. 127-145, 2024, DOI:10.32604/fdmp.2023.030137

Abstract Aiming to mitigate the aerodynamic lift force imbalance between pantograph strips, which exacerbates wear and affects the current collection performance of the pantograph-catenary system, a study has been conducted to support the beam deflector optimization using a combination of experimental measurements and computational fluid dynamics (CFD) simulations. The results demonstrate that the size, position, and installation orientation of the wind deflectors significantly influence the amount of force compensation. They also indicate that the front strip deflectors should be installed downwards and the rear strip deflectors upwards, thereby forming a “π” shape. Moreover, the lift force compensation provided by the wind… More >

Shiyu Miao^1,2,3, Xiao Liu⁴, Xiaoya Feng⁶, Haowen Shi^1,2,3, Wei Luo^1,2,3,*, Peng Liu⁵

FDMP-Fluid Dynamics & Materials Processing, Vol.19, No.7, pp. 1735-1751, 2023, DOI:10.32604/fdmp.2023.025681

Abstract At present, the optimization of the plunger mechanism is shale gas wells is mostly based on empirical methods, which lack a relevant rationale and often are not able to deal with the quick variations experienced by the production parameters of shale gas wells in comparison to conventional gas wells. In order to mitigate this issue, in the present work, a model is proposed to loosely couple the dynamics of gas inflow into shale gas wells with the dynamics of the liquid inflow. Starting from the flow law that accounts for the four stages of movement of the plunger, a dynamic… More > Graphic Abstract

Sachin Sharma^1,*, Meena Malik², Chander Prabha³, Amal Al-Rasheed⁴, Mona Alduailij⁴, Sultan Almakdi⁵

CMC-Computers, Materials & Continua, Vol.75, No.1, pp. 393-407, 2023, DOI:10.32604/cmc.2023.033536

Abstract Watermarking of digital images is required in diversified applications ranging from medical imaging to commercial images used over the web. Usually, the copyright information is embossed over the image in the form of a logo at the corner or diagonal text in the background. However, this form of visible watermarking is not suitable for a large class of applications. In all such cases, a hidden watermark is embedded inside the original image as proof of ownership. A large number of techniques and algorithms are proposed by researchers for invisible watermarking. In this paper, we focus on issues that are critical… More >

Dapeng Zhang¹, Bowen Zhao^2,*, Keqiang Zhu³

FDMP-Fluid Dynamics & Materials Processing, Vol.19, No.3, pp. 603-617, 2023, DOI:10.32604/fdmp.2022.023919

Abstract Pipelines are widely used for transporting oil resources in the context of offshore oil exploitation. The pipeline stress-strength analysis is an important stage in related design and ensuing construction techniques. In this study, assuming representative work environment parameters, pipeline lifting operations are investigated numerically. More specifically, a time-domain coupled dynamic analysis method is used to conduct a hydrodynamic analysis under different current velocities and wave heights. The results show that proper operation requires the lifting points are reasonably set in combination with the length of the pipeline and the position of the lifting device on the construction ship. The impact… More > Graphic Abstract

R. Anandha Murugan^1,*, B. Sathyabama²

Intelligent Automation & Soft Computing, Vol.36, No.1, pp. 353-368, 2023, DOI:10.32604/iasc.2023.032355

Abstract Improved picture quality is critical to the effectiveness of object recognition and tracking. The consistency of those photos is impacted by night-video systems because the contrast between high-profile items and different atmospheric conditions, such as mist, fog, dust etc. The pictures then shift in intensity, colour, polarity and consistency. A general challenge for computer vision analyses lies in the horrid appearance of night images in arbitrary illumination and ambient environments. In recent years, target recognition techniques focused on deep learning and machine learning have become standard algorithms for object detection with the exponential growth of computer performance capabilities. However, the… More >

Shengjun Deng^1,2,3, Haolin Chen¹, Xiaonan Gong², Jiajin Zhou², Xiangdong Hu⁴, Gang Jiang^1,*

CMES-Computer Modeling in Engineering & Sciences, Vol.132, No.1, pp. 251-266, 2022, DOI:10.32604/cmes.2022.020388

Abstract Freeze-sealing pipe roof method is applied in the Gongbei tunnel, which causes the ground surface uplift induced by frost heave. A frost heaving prediction approach based on the coefficient of cold expansion is proposed to simulate the ground deformation of the Gongbei tunnel. The coefficient of cold expansion in the model and the frost heaving rate from the frost heave test under the hydration condition can achieve a good correspondence making the calculation result closer to the actual engineering. The ground surface uplift along the lateral and longitudinal direction are respectively analyzed and compared with the field measured data to… More >

Guansi Liu^1,2, Keqin Ding^2,*, Hui Jin^1,*, Fangxiong Tang², Li Chen²

Structural Durability & Health Monitoring, Vol.16, No.2, pp. 145-161, 2022, DOI:10.32604/sdhm.2022.022241

Abstract With the construction of automated docks, health monitoring technology as a parallel safety assurance technology for unmanned hoisting machinery has become a hot spot in the development of the industry. Hoisting machinery has a huge structure and numerous welded joints. The complexity and nonlinearity of the welded structure itself makes the structural failure parts random and difficult to arrange for monitoring sensors. In order to solve the problem of effectiveness and stability of the sensor arrangement method for monitoring the structure of hoisting machinery. Using the global and local search capabilities enhanced by the complementary search mechanism, a structural vibration… More >