Numerical Design and Performance Prediction of Low Specific Speed Centrifugal Pump Impeller

Yongxue, Zhang,Xin, Zhou,Zhongli, Ji,Cuiwei, Jiang Korean Society for Fluid machinery 2011 International journal of fluid machinery and syste Vol.4 No.1

In this paper, Based on Two-dimensional Flow Theory, adopting quasi-orthogonal method and point-by-point integration method to design the impeller of the low specific speed centrifugal pump by code, and using RANS (Reynolds Averaged N-S) Equation with a standard k-${\varepsilon}$ two-equation turbulence model and log-law wall function to solve 3D turbulent flow field in the impeller of the low specific speed pump. An analysis of the influences of the blade profile on velocity distributions, pressure distributions and pump performance and the investigation of the flow regulation pattern in the impeller of the centrifugal pump are presented. And the result shows that this method can be used as a new way in low speed centrifugal pump impeller design.

Continuous Query Processing over Multi-Dimensional Sensing Data Stream

Yongxu Piao(박영욱),Wooseok Ryu(류우석),Haipeng Zhang(장해붕),Bonghee Hong(홍봉희) 한국정보과학회 2010 한국정보과학회 학술발표논문집 Vol.37 No.1A

Numerical studies on cavitation behavior in impeller of centrifugal pump with different blade profiles

Song, Pengfei,Zhang, Yongxue,Xu, Cong,Zhou, Xin,Zhang, Jinya Korean Society for Fluid machinery 2015 International journal of fluid machinery and syste Vol.8 No.2

To investigate the influence of blade profiles on cavitation behavior in impeller of centrifugal pump, a centrifugal pump with five different blade profiles impellers are studied numerically. The impellers with five different blade profiles (single arc, double arcs, triple arcs, logarithmic spiral and linear-variable angle spiral) were designed by the in-house hydraulic design code using geometric parameters of IS 150-125-125 centrifugal pump. The experiments of the centrifugal pump have been conducted to verify numerical simulation model. The numerical results show that the blade profile lines has a weak effect on cavitation inception near blade inlet edge position, however it has the key effect on the development of sheet cavitation in impeller, and also influences the distribution of sheet cavitation in impeller channels. A slight changing of blade setting angle will induce significant difference of cavitation in impeller. The sharp changing of impeller blade setting angle causes obvious cavitation region separation near the impeller inlet close to blade suction surface and much more flow loss. The centrifugal pump with blade profile of setting angle gently changing (logarithmic spiral) has the super cavitation performance, which means smaller critical cavitation number and lower vapor cavity volume fraction at the same conditions.

Numerical studies on cavitation behavior in impeller of centrifugal pump with different blade profiles

Pengfei Song,Yongxue Zhang,Cong Xu,Xin Zhou,Jinya Zhang 한국유체기계학회 2015 International journal of fluid machinery and syste Vol.8 No.2

To investigate the influence of blade profiles on cavitation behavior in impeller of centrifugal pump, a centrifugal pump with five different blade profiles impellers are studied numerically. The impellers with five different blade profiles (single arc, double arcs, triple arcs, logarithmic spiral and linear -variable angle spiral) were designed by the in-house hydraulic design code using geometric parameters of IS 150-125-125 centrifugal pump. The experiments of the centrifugal pump have been conducted to verify numerical simulation model. The numerical results show that the blade profile lines has a weak effect on cavitation inception near blade inlet edge position, however it has the key effect on the development of sheet cavitation in impeller, and also influences the distribution of sheet cavitation in impeller channels. A slight changing of blade setting angle will induce significant difference of cavitation in impeller. The sharp changing of impeller blade setting angle causes obvious cavitation region separation near the impeller inlet close to blade suction surface and much more flow loss. The centrifugal pump with blade profile of setting angle gently changing (logarithmic spiral) has the super cavitation performance, which means smaller critical cavitation number and lower vapor cavity volume fraction at the same conditions.

Optimization Design of an Ultra-Low Specific-Speed Centrifugal Pump Using Entropy Production Minimization and Taguchi Method

Cong Wang,Yongxue Zhang,Hucan Hou,Zhiyi Yuan,Ming Liu 한국유체기계학회 2020 International journal of fluid machinery and syste Vol.13 No.1

To improve the energy conversion efficiency and cavitation performance of the ultra-low specific-speed centrifugal pump (ULSSCP), the impeller-volute interaction has been studied. Blade outlet setting angle (β₂), wrap angle (φ), volute inlet width (b₃) and throat area (St) were addressed as the design parameters. The entropy production at 0.5 Q0 and NPSHc (critical net positive suction head) at 1.5 Q0 were selected as the target to characterize the energy loss and cavitation performance. The L9 (3⁴) orthogonal matrix was established via Taguchi method. Results show that the contribution ratio of φ on S/NS is the most vital, followed by b₃ and St, while the influence of β₂ is relatively small, and the design parameter combination with β₂=19°, φ=220°, b₃=12mm and St=190㎟ is the best choice for the lowest entropy production at 0.5Q0 and NPSHc. At last, the optimization design reduces the loss greatly before and after cavitation by alleviation of vortex generation and backflow intensity.

Using tyrosinase as a tri-modality reporter gene to monitor transplanted stem cells in acute myocardial infarction

Mei Liu,Yichun Wang,Mengting Li,Hongyan Feng,Qingyao Liu,Chunxia Qin,Yongxue Zhang,Xiaoli Lan 생화학분자생물학회 2018 Experimental and molecular medicine Vol.50 No.-

The study aimed to investigate the feasibility of noninvasive monitoring of bone marrow mesenchymal stem cells (MSCs) transduced with the tyrosinase reporter gene for acute myocardial infarction (AMI) with photoacoustic imaging (PAI), magnetic resonance imaging (MRI), and positron emission tomography (PET) in vitro and in vivo. MSCs were transduced with a lentivirus carrying a tyrosinase reporter gene. After transduction, the rate of 18F-5-fluoro-N-(2- [diethylamino]ethyl)picolinamide (18F-5-FPN) uptake was measured. PAI and MRI of stable cell lines expressing tyrosinase (TYR-MSCs) were performed in vitro. An AMI model was induced and verified. TYR-MSCs and MSCs were injected into the margins of the infarcted areas, and PAI, MRI, and PET images were acquired 1, 7, 14, 21, and 28 days after cell injection. Sham-operated models without injection were used as the control group. TYR-MSCs showed noticeably higher uptake of 18F-5-FPN and stronger signals in T1-weighted MRI and PAI than non-transduced MSCs. In vivo studies revealed prominent signals in the injected area of the infarcted myocardium on PAI/MRI/PET images, whereas no signal could be seen in rats injected with non-transduced MSCs or sham-operated rats. The uptake values of 18F-5-FPN in vivo showed a slight decrease over 28 days, whereas MRI and PAI signal intensity decreased dramatically. MSCs stably transduced with the tyrosinase reporter gene could be monitored in vivo in myocardial infarction models by PET, MRI, and PAI, providing a feasible and reliable method for checking the viability, location, and dwell time of transplanted stem cells.

Highly transparent, organic-inorganic hybrid UV-curable coating materials with amphiphobic characteristics

Jeong, Keuk-Min,Park, Sung Soo,Nagappan, Saravanan,Min, Guoquan,Zhang, Yongxu,Qu, Minming,Zhang, Yan,Ha, Chang-Sik Elsevier Sequoia 2019 Progress in organic coatings Vol.134 No.-

<P><B>Abstract</B></P> <P>Highly transparent organic-inorganic hybrid UV-curable coating formulations were obtained using silica particles with different functional groups, such as methyl group, long alkyl chain, benzene ring, isobutyl group, and fluorine group. Their surface chemical structures were analyzed by attenuated total reflection-flourier transform infrared spectroscopy and X-ray photoelectron spectroscopy. The surface morphology of the hybrid UV-curable coating formulated materials was observed by atomic force microscopy and high-resolution scanning electron microscopy. The hydrophobic and oleophobic properties were investigated by contact angle measurements using water, hexadecane, and artificial fingerprint solution. The prepared hybrid UV-curable coating materials exhibited excellent transparency, good hydrophobic, and oleophobic properties in addition to the high thermal stability and high pencil hardness up to 8H. In particular, the hybrid UV-curable coating materials with a small amount of fluorine-functionalized silica showed balanced coating performance, such as high pencil hardness (6 H) and good amphiphobic properties (static contact angles in water (135°), oil (100°), and artificial fingerprint solution (114°)), as well as excellent transparency of more than 95% of transmittance.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Surface morphology, amphiphobicity, scratch resistance, and transparency were controlled by functionalized silica particles. </LI> <LI> Alkyl chain length on surface of silica particle changed surface roughness, which can impart a physical resistance effect. </LI> <LI> UV curable silica hybrid coating materials exhibited high contact angles in water, oil, artificial fingerprint solution. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>