Three-dimensional dynamics of vortex-induced vibration of a pipe with internal flow in the subcritical and supercritical regimes

Jinlong Duan,Ke Chen,Yunxiang You,Renfeng Wang,Jinlong Li 대한조선학회 2018 International Journal of Naval Architecture and Oc Vol.10 No.6

The Three-dimensional (3-D) dynamical behaviors of a fluid-conveying pipe subjected to vortex-induced vibration are investigated with different internal flow velocity v. The values of the internal flow velocity are considered in both subcritical and supercritical regimes. During the study, the 3-D nonlinear equations are discretized by the Galerkin method and solved by a fourth-order Runge-Kutta method. The results indicate that for a constant internal flow velocity v in the subcritical regime, the peak Cross-flow (CF) amplitude increases firstly and then decrease accompanied by amplitude jumps with the increase of the external reduced velocity. While two response bands are observed in the In-line (IL) direction. For the dynamics in the lock-in condition, 3-D periodic, quasi-periodic and chaotic vibrations are observed. A variety of CF and IL responses can be detected for different modes with the increase of v. For the cases studied in the supercritical regime, the dynamics shows a great diversity with that in the subcritical regime. Various dynamical responses, which include 3-D periodic, quasi-periodic as well as chaotic motions, are found while both CF and IL responses are coupled while v is beyond the critical value. Besides, the responses corresponding to different couples of m1 and m2 are obviously distinct from each other.

Current Situation of Low-Carbon Finance in China

CHEN Jinlong,WANG Chengliang 동아대학교 동아시아연구원 2011 동아시아 : 비교와 전망 Vol.10 No.1

This paper does a research on the current situation of low-carbon finance development in China from prospects of low-carbon finance policy system, carbon finance market system and carbon finance organizational service system, which enable us to draw conclusions as: (1)there are very few matching financial policies though the macro policy is generally in favor of carbon finance; (2)because the carbon finance market is at the starting stage, its development is imperfect in all aspects; (3) the carbon finance organizational service must be improved in many aspects , since few products and services of carbon finance is yet provided in the sector of finance except for banking and securities.

Three-dimensional dynamics of vortex-induced vibration of a pipe with internal flow in the subcritical and supercritical regimes

Duan, Jinlong,Chen, Ke,You, Yunxiang,Wang, Renfeng,Li, Jinlong The Society of Naval Architects of Korea 2018 International Journal of Naval Architecture and Oc Vol.10 No.6

The Three-dimensional (3-D) dynamical behaviors of a fluid-conveying pipe subjected to vortex-induced vibration are investigated with different internal flow velocity ${\nu}$. The values of the internal flow velocity are considered in both subcritical and supercritical regimes. During the study, the 3-D nonlinear equations are discretized by the Galerkin method and solved by a fourth-order Runge-Kutta method. The results indicate that for a constant internal flow velocity ${\nu}$ in the subcritical regime, the peak Cross-flow (CF) amplitude increases firstly and then decrease accompanied by amplitude jumps with the increase of the external reduced velocity. While two response bands are observed in the In-line (IL) direction. For the dynamics in the lock-in condition, 3-D periodic, quasi-periodic and chaotic vibrations are observed. A variety of CF and IL responses can be detected for different modes with the increase of ${\nu}$. For the cases studied in the supercritical regime, the dynamics shows a great diversity with that in the subcritical regime. Various dynamical responses, which include 3-D periodic, quasi-periodic as well as chaotic motions, are found while both CF and IL responses are coupled while ${\nu}$ is beyond the critical value. Besides, the responses corresponding to different couples of ${\mu}_1$ and ${\mu}_2$ are obviously distinct from each other.

ENGINE SPEED REGULATION DURING GEAR SHIFT PROCESS OF TORQUE DECOUPLED HEV USING TRIPLE-STEP NONLINEAR METHOD

Jinlong Hong,Liang Lu,Bingzhao Gao,Lin Zhang,Hong Chen 한국자동차공학회 2021 International journal of automotive technology Vol.22 No.2

For the torque decoupled hybrid electric vehicles (HEVs) equipped with automated manual transmission (AMT), the motor torque can be used to compensate for traction loss during gear shift. Thus, engine speed regulation can be used to achieve speed synchronization, and the clutch can be removed, which simplifies the overall structure of AMT. A triple-step nonlinear method is proposed in this paper to improve the engine speed tracking accuracy, which utilizes the steady-state, reference trajectory dynamics, and the tracking error information comprehensively. By the expense of the intake manifold pressure tracking performance, the developed controller can guarantee the asymptotic convergence of the engine speed tracking error. After the triple-step controller is deduced, it is verified through co-simulation between AMT HEV plant model in AMESim and controller model in Simulink. The simulation results demonstrate that the proposed controller can exert the advantages of the two control inputs: throttle opening α and spark advance deviation Δθ, and certificate the overall gear shift quality, including shift time and vehicle jerk.

Supplementing Vitamin E to the Ration of Beef Cattle Increased the Utilization Efficiency of Dietary Nitrogen

Wei, Chen,Lin, Shixin,Wu, Jinlong,Zhao, Guangyong,Zhang, Tingting,Zheng, Wensi Asian Australasian Association of Animal Productio 2016 Animal Bioscience Vol.29 No.3

The objectives of the trial were to investigate the effects of supplementing vitamin E (VE) on nutrient digestion, nitrogen (N) retention and plasma parameters of beef cattle in feedlot. Four growing Simmental bulls, fed with a total mixed ration composed of corn silage and concentrate mixture as basal ration, were used as the experimental animals. Four levels of VE product, i.e. 0, 150, 300, 600 mg/head/d (equivalent to 0, 75, 150, 300 IU VE/head/d), were supplemented to the basal ration (VE content 38 IU/kg dry matter) in a $4{\times}4$ Latin square design as experimental treatments I, II, III and IV, respectively. Each experimental period lasted 15 days, of which the first 12 days were for pretreatment and the last 3 days for sampling. The results showed that supplementing VE did not affect the nutrient digestibility (p>0.05) whereas decreased the urinary N excretion (p<0.01), increased the N retention (p<0.05) and tended to increase the microbial N supply estimated based on the total urinary purine derivatives (p = 0.057). Supplementing VE increased the plasma concentrations of VE, glucose and triglycerol (TG) (p<0.05) and tended to increase the plasma concentration of total protein (p = 0.096) whereas did not affect the plasma antioxidant indices and other parameters (p>0.05). It was concluded that supplementing VE up to 300 IU/head/d did not affect the nutrient digestibility whereas supplementing VE at 150 or 300 IU/head/d increased the N retention and the plasma concentrations of VE and TG (p<0.05) of beef cattle.

A Decupled PQ Control strategy of Voltage - Controlled Inverters

Yang Chen,Jinbin Zhao,Jinlong Wang,Keqing Qu,Shuuichi Ushiki,Masaaki Ohshima 전력전자학회 2015 ICPE(ISPE)논문집 Vol.2015 No.6

This paper deals with problems caused by high distributed generation penetration and proposes a simple and precise PQ control strategy for voltage-controlled inverters in micro grids. The widely-used current-controlled inverters cannot provide voltage support for micro grids and have to develop seamless transfer strategy between gird connected mode and islanded mode. A voltage-controlled inverter is raised in the paper due to the problems. The new inverter can be regarded as a voltage source cascaded with controllable output impedance. By adopting a new phase-locked loop, the output voltage amplitude and frequency are well decoupled. Thus output active and reactive powers are decoupled satisfactory. The output response is fast and precise. The idea is verified by simulation and experiment results.

Metal organic frameworks template-directed fabrication of rod-like hollow BiOClxBr1x with adjustable band gap for excellent photocatalytic activity under visible light

Ze Luo,Jinlong Li,Guozhe Sui,Yan Zhuang,Dongxuan Guo,Rongping Xu,Shuang Liang,Hong Yao,Chao Wang,Shijie Chen 한국화학공학회 2022 Korean Journal of Chemical Engineering Vol.39 No.8

Developing an efficient, environmentally friendly, and pollution-free catalyst with excellent visible light catalyticactivity is a promising strategy for dye wastewater treatment. Herein, the rod-like hollow BiOClxBr1x (x=1, 0.75, 0.5,0.25, 0), with an adjustable band gap, was successfully prepared using Bi-based metal-organic framework as template. The corresponding hollow assembly and introduction of Br imparted valuable structural advantages and intrinsic characteristicsfor improved photocatalytic activity. Significantly, the degradation efficiency of BiOCl0.5Br0.5 for the RhodamineB (RhB) solution reached 92% under visible light illumination for 90 min, which is considerably higher than that ofCAU-17-derived Bi2O3 and BiOCl. Overall, these findings shed fundamental insight on constructing novel photocatalystswith excellent visible light driven photocatalytic activity and offered a new method for treating dye wastewater.

SNPs in the coding region of bovine MGAT2 gene are associated with body weight and weight gain

Lian Qu,Mingjuan Yang,Jinlong Zhu,Junxia Liu,Mijie Li,Liangzhi Zhang,Xianyong Lan,Chuzhao Lei,Chunlei Zhang,Hong Chen 한국유전학회 2011 Genes & Genomics Vol.33 No.3

Monoacylglycerol acyltransferase 2 (MGAT2), as a candidate gene for quantitative traits, relates to dietary fat uptake, lipids synthesis and storage, which plays a major role in the absorption of dietary fat by catalyzing the resynthesis of triacylglycerol in enterocytes. In this study, based on DNA pool sequencing and PCR‐RFLP methods, polymorphisms of the MGAT2 gene were detected in 1145 Chinese indigenous cattle. The results revealed two novel mutations located on exon 1and exon 5 (NM_001099136.1:m.84G>T and 756A>G). Hence, we described the HaeIII forced PCR–RFLP method in exon1 and a MluI PCR–RFLP method in exon5 to detect them. In addition, the associations of these polymorphisms with growth traits were evaluated in Nanyang cattle. The results showed that only HaeIII locus was associated with body weight and average daily gain aged 6 months, and individuals with genotype TT showed significantly higher body weight and average daily gain than those with genotype GG.

Experimental study of internal solitary wave loads on the semi-submersible platform

Zhang Jingjing,Liu Yi,Chen Ke,You Yunxiang,Duan Jinlong 대한조선학회 2021 International Journal of Naval Architecture and Oc Vol.13 No.1

A prediction method, based on the Morison equation as well as Froude-Krylov formula, is presented to simulate the loads acting on the columns and caissons of the semi-submersible platform induced by Internal SolitaryWave (ISW) respectively. Combined with the experimental results, empirical formulas of the drag and inertia coefficients in Morison equation can be determined as a function of the Keulegan eCarpenter (KC) number, Reynolds number (Re) and upper layer depth h1=h respectively. The experimental and calculated results are compared. And a good agreement is observed, which proves that the present prediction method can be used for analyzing the ISW-forces on the semi-submersible platform. Moreover, the results also demonstrate the layer thickness ratio has a significant effect upon the maximum horizontal forces on the columns and caissons, but both minimum horizontal and vertical forces are scarcely affected. In addition, the incoming wave directions may also contribute greatly to the values of horizontal forces exerted on the caissons, which can be ignored in the vertical force analysis.

Synthesis of 1, 4, 7-triazaheptane derivative and its corrosion inhibition for mild steel in the hydrochloric medium

Jiaxin Wena,Xin Zhang,Jinlong Chen,Ting Liu,Yi Zhou,Lingjie Li 한국공업화학회 2022 Journal of Industrial and Engineering Chemistry Vol.107 No.-

To exploit the advanced corrosion inhibitor for mild steel in acidic solution, N, N, N, N, N′-pentakis (2-hydroxyethyl)-1,4,7-triazaheptane (PHET) was synthesized by a facile process, which was confirmed by FT-IR, NMR and EI-MS. Inhibition effect of PHET was examined on mild steel in 1.0 M HCl solution by using weight loss, electrochemical tests and surface analyses. The results showed that the optimal concentration of PHET in HCl solution was 400 mg/L corresponding to the inhibitive efficiency of 93% at 293 K. PHET presented superior and durable corrosion inhibition performance for mild steel. Meanwhile, PHET acted as a mixed-type inhibitor which affects both anodic and cathodic reactions of the corrosion process. PHET could be absorbed on mild steel through forming complexes with ferrous ions that acted as protective film, which was supported by UV–vis and XPS analyses. The adsorption process of PHET molecules on mild steel, following Langmuir adsorption isotherm, was an exothermal process and belonged to mixed adsorption mechanisms ( =-31.78 kJ mol−1, 293 K) between physisorption and chemisorption. Besides, theoretical calculations were conducted to give further investigation on the inhibition mechanism of PHET and elucidated the adsorption behaviour of PHET. PHET synthesized in this work also can be extended to use for the corrosion protection of other metals in acidic medium.