Juanjuan Wang, Yajuan Jia^*, Jiangping Nan

FDMP-Fluid Dynamics & Materials Processing, Vol.16, No.6, pp. 1161-1175, 2020, DOI:10.32604/fdmp.2020.010328

Abstract The present study aims at improving the accuracy of weather forecast by providing useful information on the behavior and response of a sounding temperature sensor. A hybrid approach relying on Computational Fluid Dynamics and a genetic algorithm (GA) is used to simulate the system represented by the bead thermistor and the surrounding air. In particular, the influence of different lead angles, sensor lead length, and lead number is considered. The results have shown that when the length of the lead wire of the bead thermistor is increased, the radiation temperature rise is reduced; when the number of lead wire is… More >

Yukun Lv, Jiaxi Yang^*, Jing Wang

FDMP-Fluid Dynamics & Materials Processing, Vol.16, No.6, pp. 1191-1202, 2020, DOI:10.32604/fdmp.2020.010302

Abstract The combustion of pulverized coal inevitably produces dust and other harmful substances. For these reasons, the optimization of de-dusting procedure and equipments is an aspect of crucial importance towards the final goal of making this source of energy more sustainable. In the present work, the behaviour of a “bag filter” is simulated using Computational Fluid Dynamics (CFD). More specifically, three possible approaches are used, differing with respect to the level of fidelity and the partial utilization of empirical data. The outcome of these simulations is mutually compared and finally discussed critically in the light of available experimental results. More >

Chongfei Sun¹, Jianzhong Shang¹, Zirong Luo¹, Xin Li^2,*, Zhongyue Lu¹, Guoheng Wu¹

FDMP-Fluid Dynamics & Materials Processing, Vol.16, No.6, pp. 1147-1159, 2020, DOI:10.32604/fdmp.2020.09937

Abstract Small moving vehicles represent an important category of marine engineering tools and devices (equipment) typically used for ocean resource detection and maintenance of marine rights and interests. The lack of efficient power supply modes is one of the technical bottlenecks restricting the effective utilisation of this type of equipment. In this work, the performance characteristics of a new type of elastic-blade/wave-energy converter (EBWEC) and its core energy conversion component (named wave energy absorber) are comprehensively studied. In particular, computational fluid dynamics (CFD) simulations and experiments have been used to analyze the hydrodynamics and performance characteristics of the EBWEC. The pressure… More >

Yue Zhou¹, Pengfei Ju^2,3,*

FDMP-Fluid Dynamics & Materials Processing, Vol.16, No.6, pp. 1273-1283, 2020, DOI:10.32604/fdmp.2020.09666

Abstract The effects of the wall emissivity on aerodynamic heating in a scramjet are analyzed. The supersonic turbulent combustion flow including radiation is solved in the framework of a decoupled strategy where the flow field is determined first and the radiation field next. In particular, a finite difference method is used for solving the flow while a DOM (iscrete ordinates method) approach combined with a WSGGM (weighted sum of gray gases) model is implemented for radiative transfer. Supersonic nonreactive turbulent channel flows are examined for a DLR hydrogen fueled scramjet changing parametrically the wall emissivity. The results indicate that the wall… More >

Youxin Li^*

FDMP-Fluid Dynamics & Materials Processing, Vol.16, No.6, pp. 1129-1145, 2020, DOI:10.32604/fdmp.2020.09437

Abstract In order to explore the impact of different structural design parameters and environmental factors on the performance of the hydrostatic guide rail, the flow field inside its oil chamber is simulated, which provides direction and guidance for the design and optimization of the guide rail system. Based on the theory of fluid lubrication and the Reynolds equation, numerical simulations are performed through a mathematical model. The results suggest that the bearing capacity of the oil film increases with the oil supply pressure. The film thickness and the film stiffness share a positive correlation. Different oil film thickness and different input… More >

Xiaorui Cheng^1,2,*, Yimeng Jiang¹, Min Li¹, Shuyan Zhang¹

FDMP-Fluid Dynamics & Materials Processing, Vol.16, No.5, pp. 1047-1061, 2020, DOI:10.32604/fdmp.2020.010695

Abstract The influence of the axial mount position of the guide vane on the pressure fluctuation in a nuclear pump (AP1000) is investigated. The characteristics of the three-dimensional flow inside the nuclear pump are analyzed by means of numerical simulation. Results indicate that when the axial relative distance between the guide vane and the pumping chamber is reduced, in conditions of “small flow,” the efficiency of the pump increases, the pressure inside the pumping chamber decreases, while the losses related to the guide vane grow. Under large flow conditions, as the efficiency of the pump decreases, the losses for the guide… More >

Miao He^1,2, Yihang Zhang^1,*, Mingbiao Xu^1,2,*, Jun Li³

FDMP-Fluid Dynamics & Materials Processing, Vol.16, No.5, pp. 1031-1046, 2020, DOI:10.32604/fdmp.2020.011145

Abstract This study presents a new multiphase flow model with transient heat transfer and pressure coupling to simulate HTHP (high temperature and high pressure) sour gas “kicks” phenomena. The model is intended to support the estimation of wellbore temperature and pressure when sour gas kicks occur during drilling operation. The model considers sour gas solubility, phase transition and effects of temperature and pressure on the physical parameters of drilling fluid. Experimental data for a large-diameter pipe flow are used to validate the model. The results indicate that with fluid circulation, the annulus temperature with H₂S kicks is the highest, followed by… More >

Xiaobin Shu, Miaomiao Ren^*

FDMP-Fluid Dynamics & Materials Processing, Vol.16, No.5, pp. 1019-1029, 2020, DOI:10.32604/fdmp.2020.09564

Abstract In order to address typical problems due to the huge demand of oil for consumption in traditional internal combustion engines, a new more efficient combustion mode is proposed and studied in the framework of Computational Fluid Dynamics (CFD). Moreover, a Non-dominated Sorting Genetic Algorithm (NSGA-II) is applied to optimize the related parameters, namely, the engine methanol ratio, the fuel injection time, the initial temperature, the Exhaust Gas Re-Circulation (EGR) rate, and the initial pressure. The so-called Conventional Diesel Combustion (CDC), Homogeneous Charge Compression Ignition (HCCI) and the Reactivity Controlled Compression Ignition (RCCI) combustion modes are compared. The results show that… More >

Lingzhi Yu¹, Yunqing Gu^1,*, Jiegang Mou¹, Denghao Wu¹, Zhenfu Chen², Yun Ren³

FDMP-Fluid Dynamics & Materials Processing, Vol.16, No.5, pp. 1007-1018, 2020, DOI:10.32604/fdmp.2020.09509

Abstract In order to improve the performances of a cycloid gerotor pump, the variations of the radial force induced by different rotating speeds and outlet pressures are analyzed numerically. Using the numerical simulations as a basis, an improved oil inlet and outlet groove structure is proposed. The results show that the radial force decreases with the decrease of the outlet pressure and of the rotor speed. Compared with the original model, the large-end oil inlet line and pressure line of the new oil groove are claw-shaped. This configuration can effectively weaken the pressure changes inside the gerotor pump and reduce accordingly… More >

Minxuan Li¹, Jing Sun^1,*, Dehua Liu¹, Yang Li¹, Kuidong Li², Wei Liu², Jialin Xiao², Jiani Hu³

FDMP-Fluid Dynamics & Materials Processing, Vol.16, No.5, pp. 993-1005, 2020, DOI:10.32604/fdmp.2020.010443

Abstract Existing “evaluation indicators” are selected and combined to build a model to support the optimization of shale gas horizontal wells. Towards this end, different “weighting methods”, including AHP and the so-called entropy method, are combined in the frame of the game theory. Using a relevant test case for the implementation of the model, it is shown that the horizontal section of the considered well is in the middle sweet spot area with good physical properties and fracturing ability. In comparison with the FSI (flow scanner Image) gas production profile, the new model seems to display better abilities for the optimization… More >