Numerical simulations and surrogate-based optimization of cavitation performance for an aviation fuel pump

Xing’an Zhao,Biao Huang,Tairan Chen,Guoyu Wang,Deming Gao,Jing Zhao 대한기계학회 2017 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.31 No.2

We used computational modeling to investigate the cavitation performance of an aviation fuel pump, and optimize structural parameters using the surrogate-based method. In the numerical simulation, a rotation-curvature correction was adapted to the k-ε turbulence model, and a four-component surrogate fuel was selected to reproduce the physical properties of the China RP-3 kerosene. Then the performance of the aviation fuel pump was predicted. In the optimization, based on the series of the numerical results, Surrogate-based analysis and optimization (SBAO) was used to optimize the structural parameters of the fuel pump (the variation of the outlet blade angle for the inducer △β b1 and the variation of the inlet blade angle for the impeller △β b2 ). The results show that the prediction of cavitation performance agrees well with the experimental data. The results show that cavitation areas are mainly distributed in the inlet of the inducer. The volume of cavities grows with the decreasing NPSHa. The head of the fuel pump has a sudden head-drop when NPSHa ≤ 5.64 m. Furthermore, the surrogate-based approach is available in structural optimization of the fuel pump. The cavitation performance of the optimized pump improved about 22 % with a little drop of head coefficient when △β b1 = 4.33° and △β b2 = 3.24°. The numerical approach employed in this paper can accurately predict the cavitating flow of the high rotating speed fuel pump and the surrogate-based method is available in the structural optimization for a better cavitation performance.

Muscle-derived Stem Cells Differentiate into Functional Smooth Muscle Cells for Ureter Tissue Engineering: An Experimental Study

Zhan-Kui Zhao,Hong-Lian Yu,Fei Xiao,Shi-Wen Li,Wen-Biao Liao,Kai-Liang Zhao 한국생물공학회 2012 Biotechnology and Bioprocess Engineering Vol.17 No.3

We assessed the ability of muscle-derived stem cells (MDSC) to differentiate into smooth muscle cells (SMC) and their potential to promote the regeneration of smooth muscle with a vessel extracellular matrix (VECM)for tissue engineering of the ureter. MDSC were isolated,proliferated, and identified by flow cytometry. SMC phenotype differentiation was induced with a smooth muscle induction medium. Gene expression was evaluated by real-time quantitative polymerase chain reaction (PCR)and Western blot studies. The VECM was obtained by a decellularization process, and cytotoxic effects were evaluated by exposing the induced cells to a VECM extract. The induced cells were seeded onto VECM in vitro for 1 week, and then the compound grafts were used for ureter reconstitution in vivo. The grafts were obtained for histological studies at 2, 4, 8, and 16 weeks post-operation. Intravenous urography was used to evaluate renal function and ureteral patency. Flow cytometry demonstrated that the MDSC expressed Sca-1 and desmin, but did not express CD45. After induction, SMC phenotype gene expression was confirmed in the induced cells by real-time quantitative PCR and Western blot studies. VECM exhibited a nontoxic effect on the induced cells in vitro. At 16 weeks postoperation,a histological evaluation showed that multilayered urothelium and organized muscle fiber bundles had formed in the grafts. Intravenous urography demonstrated no evidence of ureteral stricture or hydroureteronephrosis. These results demonstrate that MDSC can be induced into SMC and that this was useful for promoting regeneration of smooth muscles for ureter tissue engineering. We assessed the ability of muscle-derived stem cells (MDSC) to differentiate into smooth muscle cells (SMC) and their potential to promote the regeneration of smooth muscle with a vessel extracellular matrix (VECM)for tissue engineering of the ureter. MDSC were isolated,proliferated, and identified by flow cytometry. SMC phenotype differentiation was induced with a smooth muscle induction medium. Gene expression was evaluated by real-time quantitative polymerase chain reaction (PCR)and Western blot studies. The VECM was obtained by a decellularization process, and cytotoxic effects were evaluated by exposing the induced cells to a VECM extract. The induced cells were seeded onto VECM in vitro for 1 week, and then the compound grafts were used for ureter reconstitution in vivo. The grafts were obtained for histological studies at 2, 4, 8, and 16 weeks post-operation. Intravenous urography was used to evaluate renal function and ureteral patency. Flow cytometry demonstrated that the MDSC expressed Sca-1 and desmin, but did not express CD45. After induction, SMC phenotype gene expression was confirmed in the induced cells by real-time quantitative PCR and Western blot studies. VECM exhibited a nontoxic effect on the induced cells in vitro. At 16 weeks postoperation,a histological evaluation showed that multilayered urothelium and organized muscle fiber bundles had formed in the grafts. Intravenous urography demonstrated no evidence of ureteral stricture or hydroureteronephrosis. These results demonstrate that MDSC can be induced into SMC and that this was useful for promoting regeneration of smooth muscles for ureter tissue engineering.

Research on ball valve and misaligned guide vane devices to improve the “S” characteristics of a pump turbine

Biao Yang,Lin Zhao,Tian Tian,Yankui Qin,Changyu Liu 대한기계학회 2022 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.36 No.5

The “S” characteristics of a pump turbine may result in certain problems, such as excessive water hammer pressure, unstable no-load operation, and difficulty in synchronization. Accordingly, a new start-up strategy based on the partial opening of a ball valve is proposed, and the calculation model of the hydraulic transition process with misaligned guide vane devices (MGV) and a ball valve is established. The emergency shutdown and turbine start-up conditions are simulated and analyzed. The ball valve can more effectively reduce the maximum inlet pressure of the volute and increase the minimum inlet pressure of the draft tube during the shutdown process compared with the MGV devices. The newly proposed strategy can also effectively reduce the amplitude of pressure fluctuation at the volute and draft tube, shorten the synchronization time, and reduce the speed overshoot during the start-up process. The ball valve can effectively improve the operating quality of the unit in the S-shaped area.

Combined effects of three novel SNPs within goat LHX3 gene on milk performance

Jin-Biao Liu,Chu-Zhao Lei,Xian-Yong Lan,Yao Xu,Zhuan-Jian Li,Hong Chen 한국유전학회 2011 Genes & Genomics Vol.33 No.5

In this study, single nucleotide polymorphisms (SNPs) of LHX3 gene were detected by DNA sequencing based on DNA pools and PCR-RFLP method in 792 goats belonging to three Chinese indigenous breeds (Guanzhong dairy, Xinong Sannen dairy, Inner Mongolia white cashmere). The results revealed three novel mutations (AY923832:g.7778A>T; g.8035T>C;g.10592C>T), which were named as P2-DraI, P3-HinfI and P4-MspI loci, respectively. The linkage disequilibrium analysis demonstrated P3-HinfI and P4-MspI loci were strongly linked (r^2>0.33) in all the analyzed populations. Each SNP produced no significant (p>0.05) effects on milk performance. However,the two-loci and three–loci combined genotypes had more profound impacts on milk yield than in separation. The individuals with diplotype AATT (P2-DraI/P3-HinfI) showed significantly (p<0.05) higher milk yield than those with diplotypes ATTT, TTTT, ATTC, and AACC. Diplotype TTCCTT (P2-DraI/P3-HinfI/P4-MspI) carriers had significantly (p<0.05) higher milk yield than those with diplotypes ATTTCC and AACCTC. These combined effects of LHX3 gene polymorphisms indicated that this gene had significant effect on milk performance and its corresponding combined diplotypes could be regarded as potential genetic markers of milk performance.

Synthesis of dimethyl carbonate from methyl carbamate and methanol using MCM-41 functionalized with sulfonic acid groups as catalyst

Wenbo Zhao,Xianye Qin,Bing Han,Biao Liu,Peichao Lian,Shuisheng Wu 한국화학공학회 2015 Korean Journal of Chemical Engineering Vol.32 No.6

The catalytic synthesis of dimethyl carbonate from methyl carbamate and methanol was investigated in a batch reactor. All of the homogeneous Brönsted acid catalysts show favorable catalytic activity. As homogeneous Brönsted acid catalyst is difficult to separate after reaction, it is converted to heterogeneous catalyst by grafting sulfonic acid groups to MCM-41 with three different methods. Their catalytic activity investigation indicated that sulfonic acid groups grafted by sulfonating with chlorosulfonic acid directly showed activity near to that of homogeneous sulfuric acid catalyst. It was further selected as a model catalyst to investigate the effect of acid amount on its catalytic activity. The results indicated that its activity was positively correlated with its acid amount.

Combined experimental and computational investigation of the cavitating flow in an orifice plate with special emphasis on surrogate-based optimization method

Xianlin Li,Biao Huang,Tairan Chen,Ying Liu,Sicong Qiu,Jing Zhao 대한기계학회 2017 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.31 No.1

We investigated the influence of geometrical parameters of the orifice plate on the cavitation structures, and optimized these parameters by using a surrogate-based model with special emphasis on the concentration of hydroxyl radical released. The results show that for the orifice plate of the hydrodynamic cavitation system, the possible location of the inception of the cavity spreads to throat and divergent section of the venturi geometry. Based on the surrogate model and global sensitivity assessment, the diameter of throat D t and diameter of inlet D in significantly influenced the size of the cavity, while the length of throat L t had little effect on both cavitation intensity and flow rate. It should be noted that when L t is decreased, the size of cavity would be slightly decreased but the flow rate increased clearly. The increase of the diverging section is in favor of the size of cavity. By comparing the experimental measurements on the concentration of Methylene blue, the optimum geometry of the orifice plate for best cavitational activity is proposed.

Zhou, T.B., <i>et al.</i> , Correction: All-Trans Retinoic Acid Treatment Is Associated with Prohibitin Expression in Renal Interstitial Fibrosis Rats. <i>Int. J. Mol. Sci.</i> 2012, <i>13</i> , 2769–2782.

Zhou, Tian-Biao,Qin, Yuan-Han,Li, Zheng-Yi,Xu, Hui-Ling,Zhao, Yan-Jun,Lei, Feng-Ying Molecular Diversity Preservation International (MD 2012 INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES Vol.13 No.12

Vibration characteristic analysis of gearbox based on dynamic excitation with eccentricity error

Wen Liu,Hang Zhao,Tengjiao Lin,Biao Gao,Yun Yang 대한기계학회 2020 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.34 No.11

In this study, the vibration characteristics of gearbox considering the eccentricity error and the friction excitation of helical gear pair were evaluated theoretically and experimentally. A geometric model of a single-stage helical gear pair with eccentricity error was established to obtain the calculation formula of the length of the dynamic contact line and the friction excitation. The multi-degree-of-freedom dynamic model of the transmission system was established considering the influences of tooth friction, support stiffness and damping, meshing stiffness and damping, static error, and dynamic tooth backlash. Then, the dynamic meshing forces of the system were obtained and applied to the gearbox for vibration response analysis using mode superposition method. A correlation test rig was developed to measure vibration under different operating conditions for verifying the correctness of the simulation models. Comparison between simulation and test was performed to demonstrate the accuracy of the proposed model in predicting vibrations. Results showed that eccentricity greatly influenced the overall vibration characteristics. The relative error between measurement and prediction can be significantly reduced by considering the eccentricity error in the dynamic model of transmission system.

Electronic effects on protective mechanism of electropolymerized coatings based on N-substituted aniline derivatives for mild steel in saline solution

Hao Liu,Baomin Fan,Zining Liu,Xiaoqi Zhao,Biao Yang,Xingwen Zheng,Hua Hao 한국공업화학회 2022 Journal of Industrial and Engineering Chemistry Vol.106 No.-

Polyaniline (PANI), poly(N-methylaniline) (PNMA) and poly(N-formylanilide) (PNFA) coatings were fabricatedover mild steel via chronoamperometric strategy in oxalate electrolyte. Scanning electron microscope(SEM), attenuated total reflection infrared spectroscopy (ATR-IR) and X-ray photoelectronspectroscopy (XPS) evidenced the polymerization of monomers. Anticorrosive effects of PANI, PNMAand PNFA coatings for steel substrate were evaluated during long-term immersion in 3.5% NaCl solutionby potentiodynamic polarization, electrochemical impedance spectroscopy (EIS) and frequency modulation(EFM). Morphological variation for coated specimens before and after immersion in NaCl solutionwas also monitored by SEM and atomic force microscope (AFM). Differentiated protection capability wereobserved for three coatings following the sequence of PNFA > PNMA > PANI. Through electrochemical andinterfacial analyses, electroactivity and physical barrier were ascertained as the critical factors, especiallythe former one, in the long-term protection capacity. Electroactivity was distinguished by the elevatedapparent current density from non-destructive EFM measurements. Furthermore, electron-donationand -withdrawal effects of N-substituents played an essential role in coating electroactivity. In detail,N-substituents improved the anodic protection and physical barrier of PNMA and PNFA coatings. Particularly, formyl with electron-withdrawal effect reinforced the anodic protection and thus the superiorthe anticorrosion efficiency of PNFA for underlying steel.

Facile Synthesis of Ag/AgCl Grafted AgBi(MoO4)2 with Enhanced Photocatalytic Performance Under Visible Light

Xu Yan,Ziyang Wu,Yong Zhao,Biao Liu,Yong Zhao 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2018 NANO Vol.13 No.08

Silver nanoparticles (NPs) and related semiconductors are a family of very important and widely applied photocatalysts. However, the preparation of high stability and activity of this photocatalyst is still a challenge. In this work, we report a stable Ag/AgCl/AgBi(MoO4)2 heterojunction photocatalyst fabricated via a simple in situ anion-exchange reaction followed by the photoreduction treatment. In the treatment of tetracycline (TC) wastewater under visible light, the AC-0.4 sample (prepared with 0.4 mmol KCl) exhibits the significantly improved activity (degradation ratio, DR of 71.3%) compared with the pristine AgBi(MoO4)2 (30% DR) and Ag/AgCl sample (synthesized by the photoreduction of AgCl) (37% DR) under identical experimental conditions. This activity promotion is from the fast interfacial electron transfer between the heterojunction phases of AgCl/AgBi(MoO4)2 and the SPR effect of Ag NPs. After five successive recycles, the AC-0.4 sample still maintains good stability and activity for TC degradation, which shows a great potential to be used in practical application. Through the ESR and controlled scavenged experiments, we found the · OH and · O- 2 are the major reactive intermediate species in the TC photodegradation reaction. Our work provides a new insight into the synthesis of stable and high efficient Ag-based heterojunction photocatalysts for the application of wastewater treatment.