Quanfu Gao^a,b , Kun Zhang^a,b,*, Liang Bi Wang^a,b

Frontiers in Heat and Mass Transfer, Vol.14, No.1, pp. 1-10, 2020, DOI:10.5098/hmt.14.29

Abstract Detailed numerical analysis is presented for natural convection heat transfer in internally finned horizontal annuli. Governing equations are discretized using the finite volume method, and solved using SIMPLE algorithm with Quick scheme. The results show that the flow and heat transfer can reach steady state when the Rayleigh number is below 2×10⁴. When the Rayleigh number is greater than 3×10⁴ , two different types of numerical solutions under the same parameters can be obtained for different initial conditions. The critical Rayleigh numbers with two different initial conditions are different from steady to unsteady solutions. The oscillatory flow undergoes several bifurcations… More >

Yuqin Wang^1,2,3,*, Luxiang Zhou³, Mengle Han¹, Lixiang Shen¹

FDMP-Fluid Dynamics & Materials Processing, Vol.19, No.9, pp. 2215-2228, 2023, DOI:10.32604/fdmp.2023.027188

Abstract The main structural parameters of the IR100-80-100A type chemical centrifugal pump have been optimized by means of an orthogonal test approach. The centrifugal pump has been modeled using the CFturbo software, and 16 sets of orthogonal-test schemes have been defined on the basis of 4 parameters, namely, the blade number, blade outlet angle, impeller outlet diameter, and impeller outlet width. Such analysis has been used to determine the influence of each index parameter on the pump working efficiency and identify a set of optimal combinations of such parameters. The internal flow field in the centrifugal pump has been simulated by… More > Graphic Abstract

Erhabor S. Idemudia¹, Babatola D. Olawa^1,*, Gail E. Wyatt², Norweeta G. Milburn²

International Journal of Mental Health Promotion, Vol.25, No.5, pp. 699-710, 2023, DOI:10.32604/ijmhp.2023.026852

Abstract It is established in the psychological literature that pre-displacement stressors, PTSD symptoms, and psychological distress are associated among internally displaced persons. However, existing studies have not demonstrated the mechanism underlying these associations. This study compared two explanatory models; one with PTSD symptoms severity explaining the indirect association between pre-displacement stressors and psychological distress, and the other with psychological distress explaining the indirect relationship between pre-displacement stressors and PTSD symptoms severity. In a cross-sectional design, 631 women (Mean age = 31.18 ± 8.59) were conveniently and purposely selected from the displaced women harboured in two camps in Borno State, Nigeria, due… More >

Xiao Sun^a, Fan-Kang Zeng^a, Jia-Bing Yang^a, Feng-Lin Zhou^a, Yu-Liang Zhang^b,*

Frontiers in Heat and Mass Transfer, Vol.17, No.1, pp. 1-6, 2021, DOI:10.5098/hmt.17.5

Abstract In order to better study the internal flow characteristics of centrifugal pump as turbine, CFX software is employed to carry out numerical simulation to obtain flow field under different working conditions for pump as turbine based on the standard k - epsilon turbulence model and the SIMPLEC algorithm. The efficiency curves of the pump and pump as turbine are obtained under different working conditions. The results show that the effciency characteristics of the pump change greatly during the process of pumping. The efficiency of the turbine is higher than that of the pump under the respective optimal operating conditions. The… More >

Namphon Pipatpaiboon^a , Teerapat Chompookham^b, Sampan Rittidech^b, Yulong Ding^c, Thanya Parametthanuwat^d, Surachet Sichamnan^a,*

Frontiers in Heat and Mass Transfer, Vol.19, No.1, pp. 1-9, 2022, DOI:10.5098/hmt.19.24

Abstract When nanofluid (NF) is used as the working fluid in a rectangular two-phase closed thermosyphon (RTPCT), the formations and heat performance of two-phase flow patterns are explored qualitatively. Silver nanoparticles were mixed with deionized water at a concentration of 0.5 wt% in the NF. Nanoparticles improved the thermal contact surface area within the base flow, allowing the base fluid to boil quickly and easily. When the working fluid was boiled, NF also demonstrated high thermal conductivity capabilities, which diffused and moved along with the dual flow patterns. As a result, these qualities improved the RTPCT's efficiency. Considering the findings of… More >

Yu-Liang Zhang^a,* , Dong-Yang Wu^b, Hai-Bing Cai^c, Can-Fei Wang^c, Fei-Wu^c, Shao-Han Zheng^d

Frontiers in Heat and Mass Transfer, Vol.20, No.1, pp. 1-5, 2023, DOI:10.5098/hmt.20.11

Abstract In this paper, based on the Mixture model, the numerical computations of the internal flow field in a sewage pump are carried out. Through numerical simulation, the turbulence flow characteristics in the sewage pump are obtained. Results show that when the particle diameter is 0.10 mm, the solid-phase concentration on the volute surface is high, and the wear is more severe. When the particle diameters are 0.15 mm and 0.20 mm, the solid-phase concentration on the volute surface is significantly higher, especially when the over-current cross-section enlarges constantly. More >

Jianfang Qi¹, Yue Li^1,3, Haibin Jin¹, Jianying Feng¹, Dong Tian¹, Weisong Mu^1,2,*

CMES-Computer Modeling in Engineering & Sciences, Vol.137, No.1, pp. 197-232, 2023, DOI:10.32604/cmes.2023.026113

Abstract An appropriate optimal number of market segments (ONS) estimation is essential for an enterprise to achieve successful market segmentation, but at present, there is a serious lack of attention to this issue in market segmentation. In our study, an independent adaptive ONS estimation method BWCON-NSDK-means++ is proposed by integrating a new internal validity index (IVI) Between-Within-Connectivity (BWCON) and a new stable clustering algorithm Natural-SDK-means++ (NSDK-means++) in a novel way. First, to complete the evaluation dimensions of the existing IVIs, we designed a connectivity formula based on the neighbor relationship and proposed the BWCON by integrating the connectivity with other two… More >

R. Prasanna^1,*, Uma Govindarajan¹, N. S. Bhuvaneswari²

Computer Systems Science and Engineering, Vol.46, No.2, pp. 1961-1979, 2023, DOI:10.32604/csse.2023.032424

Abstract In this paper, an optimized Genetic Algorithm (GA) based internal model controller-proportional integral derivative (IMC-PID) controller has been designed for the control variable to output variable transfer function of dc-dc boost converter to mitigate the effect of non-minimum phase (NMP) behavior due to the presence of a right-half plane zero (RHPZ). This RHPZ limits the dynamic performance of the converter and leads to internal instability. The IMC PID is a streamlined counterpart of the standard feedback controller and easily achieves optimal set point and load change performance with a single filter tuning parameter λ. Also, this paper addresses the influences… More >

Xiaohui Cheng¹, Haiqing Si^1,*, Yao Li¹, Peihong Zhang²

CMES-Computer Modeling in Engineering & Sciences, Vol.136, No.2, pp. 1729-1742, 2023, DOI:10.32604/cmes.2023.022694

Abstract To understand the influence of the initial release conditions on the separation characteristics of the store and improve it under high Mach number (Ma = 4) flight conditions, the overset grid method and the Realizable turbulence model coupled with an equation with six degrees of freedom are used to simulate the store released from the internal bay. The motion trajectory and the attitude angle of the store separation under the conditions of different centroid, velocity, height and control measures are given by the calculated result. Through analysis, the position of the centroid will affect the separation of the store, which needs to… More >

WEICHEN ZHAO¹, PINGFAN ZHOU¹, BENZHEN LOU¹, YAQI JIANG¹, YUANBO LI¹, MINGSHU LI¹, NOMAN SHAKOOR¹, YUKUI RUI^1,2,3,4,*

BIOCELL, Vol.47, No.3, pp. 493-502, 2023, DOI:10.32604/biocell.2023.025740

Abstract As the climate worsens and the demand for food grows, so does the interest in nanoagriculture. The interaction between plants and nanomaterials (NMs) has been extensively and intensively examined. However, stopping at the outcome of a phenomenon is often insufficient. Therefore, we introduce three important processes of nanoparticle-plant interactions: translocation, transformation, and plant metabolism. During the migration of nanoparticles, size and surface electrical properties are the main determining factors. Additionally, the interaction of nanoparticles with cell membranes is another key aspect of research. The transformation of nanoparticles in plants is mainly due to redox substances. The way that nanoparticles affect… More >