Article
Mechanics
I. A. Milne, O. Kimmoun, J. M. R. Graham, B. Molin
Summary: The study focused on the wave-induced resonant flow in a narrow gap between a stationary hull and a vertical wall. Experimental and numerical analyses showed that vortex shedding from the sharp bilge edge of the hull resulted in a damped response in the gap.
JOURNAL OF FLUID MECHANICS
(2021)
Article
Chemistry, Physical
Zhen Zhang, Juan Zhao, Xiang Ling, Jie Ma
Summary: This paper investigates the dynamic behaviors of micro-droplets impacting vertical walls in the gas channels of PEMFCs using a CLSVOF method. The effects of Weber number and impact angle on the spreading dynamics are evaluated, alongside discussing the critical conditions for the transition from spreading to rebound. The results show that both wall wettability and Weber number can affect the transition threshold, with implications for water management and performance in fuel cells.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2021)
Article
Mechanics
A. Chandel, S. P. Das
Summary: Experimental investigations on the wake of a rotating and translating sphere near a plane wall at moderate Reynolds numbers show different vortex shedding behaviors and wake structures under varying conditions, such as transition from hairpin type to shear layer vortex shedding, Kelvin-Helmholtz instability, and breakdown of larger vortical structures into smaller scales due to strong interaction of vortex rings and boundary layer.
Article
Engineering, Marine
Ran Li, Jie Gong, Wei Chen, Jie Li, Wei Chai, Chang-kyu Rheem, Xiaobin Li
Summary: Numerical simulations were conducted to investigate the vortex-induced vibrations of a two-degree-of-freedom rotating cylinder near a wall. The effects of gap ratio, reduced velocity, and rotational rate on amplitude response, wake variations, and fluid forces were analyzed. The results revealed the correlative mechanism in the wake-hydrodynamics-vibration. It was found that the wall has a dominant influence on the vortex-induced vibration, which weakens with the increase of the gap ratio and becomes negligible when H/D > 1.1.
JOURNAL OF MARINE SCIENCE AND ENGINEERING
(2023)
Article
Engineering, Mechanical
Sahreen Tahira, Ammar Mushtaq, M. Mustafa
Summary: This note presents a study on the boundary layer development of nanofluid under a generalized vortex flow using the two-phase Buongiorno model. The study reveals that the nanofluid temperature is not significantly affected by variations in diffusion coefficients, while noticeable variations in nanoparticle concentration profile are observed.
PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART E-JOURNAL OF PROCESS MECHANICAL ENGINEERING
(2022)
Article
Thermodynamics
Zhong Ma, Xiaojing Ma, Bowen Zhang, Xinpeng Xiao, Mengyao Fan
Summary: The impact of droplets on solid walls is a common phenomenon in nature, industry, and daily life. The spreading process of droplets is divided into three stages: initial deformation, inertia-dominated, and viscosity-dominated. The smoothed particle hydrodynamics (SPH) method was used to simulate the spreading of droplets under different impact conditions. The study verified the effectiveness of the method and analyzed the effects of Weber number and droplet diameter ratio on the maximum spreading diameter and central thickness. A fitting equation for the center thickness and impact time in the third stage of droplet spreading was assessed.
NUMERICAL HEAT TRANSFER PART A-APPLICATIONS
(2023)
Article
Engineering, Aerospace
Pavel Makeev, Yuri Ignatkin, Alexander Shomov
Summary: This study numerically investigates the aerodynamic characteristics of the coaxial main rotor of the Kamov Ka-32 helicopter in steep descent modes, including the vortex ring state (VRS) modes. The results are compared with experimental and calculated data from other researchers, showing a satisfactory match. The findings contribute to the existing knowledge and experience in experimental and numerical research in this field.
Article
Thermodynamics
Fei Wang, Kit Ming Lam
Summary: Experimental and numerical data were obtained for the turbulent wake velocity fields around a short wall-mounted square cylinder in a thick turbulent boundary layer. Despite good comparisons in low-order statistics of velocity fields, a satisfactory reproduction of coherent structures was not guaranteed. While spatial patterns and dynamic performance showed great similarities between PIV and LES, differences were found in terms of turbulent kinetic energy contribution.
EXPERIMENTAL THERMAL AND FLUID SCIENCE
(2021)
Article
Engineering, Civil
Tommaso Attili, Valentin Heller, Savvas Triantafyllou
Summary: The study focused on the impact of landslide-tsunamis on dams, validating wave loading and wave run-up height prediction equations through simulated experiments. New empirical equations were suggested to predict wave run-up height and overtopping volume, while novel insights on dynamic pressure and asymmetrical wave impact angles were provided.
COASTAL ENGINEERING
(2021)
Article
Thermodynamics
D. E. Khazov, A. I. Leontiev, A. G. Zditovets, N. A. Kiselev, Yu. A. Vinogradov
Summary: This paper presents an experimental and numerical analysis of a new method of energy separation. The research investigates the effects of various parameters such as initial Mach number, initial stagnation pressure, relative channel length, and Prandtl number on the energy separation. The obtained temperature difference due to the suction of a part of the flow could have potential applications in power systems with variable mass flow rates.
Article
Physics, Multidisciplinary
Lite Zhang, Zilong Feng, Mengyu Sun, Haozhe Jin, Honghui Shi
Summary: This study investigates the propagation and attenuation characteristics of a planar incident shock wave through an array of perforated plates. The results show that the intensity of the shock wave undergoes a complex process of attenuation, local enhancement, attenuation, enhancement, and attenuation. Interactions between reflected and transmitted shocks lead to the deformation and local intensification of the shock wave.
Article
Thermodynamics
Xiaojun Fan
Summary: The study established and investigated a vortex double wall cooling configuration for gas turbine blade leading edge, showing over 3 times improvement in cooling performance compared to basic straight passage double wall cooling. Different disturbing objects and rows of bridge holes can enhance local heat transfer without affecting overall cooling, and increasing bridge hole rows can bring considerable cooling improvements.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2022)
Article
Engineering, Chemical
Hongfa Sun, Zhengyu Li, Zeyu Li, Liang Huang
Summary: This paper examines the dust generation mechanism of the material unloading process through three processes, including establishing an experimental model, testing the particle motion fugitive characteristics, and analyzing the effect of different conditions. The research results show that the wall inclination angle, drop height, and outlet diameter have significant impacts on particle fugitive characteristics during bulk material loading and unloading.
Article
Mechanics
Ming Zhao, Abdullah-Al Mamoon, Helen Wu
Summary: Simulations of flow past two staggered square cylinders reveal significant effects of the degree of staggering on flow features and drag coefficients. Shear layer trapping and horseshoe vortices are observed at small gaps, while negative mean drag coefficients are only found in the tandem arrangement.
Article
Engineering, Multidisciplinary
S. Sakinder, T. Salahuddin
Summary: This paper aims to analyze the mathematical and theoretical scrutiny of non-Newtonian Williamson liquid on an asymmetry tapered channel with thermal and mass transportation. Various effects such as modified Darcy law, electro osmosis, heat generation and chemical reaction are incorporated in the formulation of the current problem. The RK-4 based shooting method is utilized to solve the nonlinear equations, and graphical results are provided to visualize the significance of different parameters.
ALEXANDRIA ENGINEERING JOURNAL
(2023)