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Effect of inlet elbow on rotation stall in waterjet ppropulsionpump

Fundamental Research 2024年第4期4卷 898-906页

作者： Wei Li Shuo Li Leilei Ji Enda Li Weidong Shi ramesh agarwal Muhammad Awais National Research Center of Pumps Jiangsu UniversityZhenjiang 212013China Institute of Fluid Engineering Equipment Technology Jiangsu UniversityZhenjiang 212009China College of Mechanical Engineering Nantong UniversityNantong 226019China departmentof Mechanical Engineering&Materials Science Washington University in StLouisSt.LouisMO6330US.

To study the influence of an elbow inlet on the rotating stall characteristics of a waterjet propulsion pump(WJPP),a three-dimensional internal flow field in a WJPP under a straight-pipe inlet and elbow inlet is numerically *** comparing the hydraulic performance of WJPP under the two inlet conditions,the internal relationship between the inlet mode and the flow pattern in the pump is *** on unsteady pressure fluctuation characteristics and wavelet analysis,the influence of the inlet mode on the rotating stall is revealed,and the stall transient propagation characteristics under critical stall conditions are *** disturbance effects of the inlet channel geometry disappear under low flow rate conditions,the main disturbance is induced by the highspeed countercurrent,and the flow pattern under the elbow inlet is better than that under the straight-pipe *** the straight-pipe inlet,the single-stall nucleus in the WJPP temporarily experiences a low-frequency and high-amplitude disturbance,which subsequently transforms into a mode of multi-stall nuclei with high-frequency circumferential *** the elbow inlet,the rotating stall always maintains a mode of high-amplitude and low-frequency disturbance,which represents the transient characteristics of a single stall core propagating in the circumferential direction inside the *** results of this study have a reference value for structural design optimization in a WJPP.

关键词： Waterjet propulsion pump Inlet condition Rotation stall Flow structure Pressurefluctuation

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Effects of Froude number and geometry on water entry of a 2-D ellipse

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Journal of Hydrodynamics 2018年第4期30卷 738-749页

作者：张旭刘沛清屈秋林王睿 ramesh K.agarwal School of Aeronautic Science and Engineering Beihang University School of Engineering and Applied Science Washington University in St.Louis

By using the finite volume method with volume of fluid model and global dynamic mesh technique, the effects of Froude number and geometry on the water entry process of a 2-D ellipse are investigated numerically. For the time history of the vertical force, the computational fluid dynamics（CFD） results match the experimental data much better than the classical potential-flow theories due to the consideration of the viscosity, turbulence, surface tension, gravity, and compressibility. The results show that the position of peak pressure on ellipse shifts from the spray root to the bottom of ellipse at a critical time. The critical time changes with the geometry and Froude number. By studying the vertical force, the ellipse water entry process can be divided into the initial and late stages based on the critical dimensionless time of about 0.1. The geometry of the ellipse plays a dominant role in the initial stage, while the Froude number is more important in the late stage of entry. The classical Wagner theory is extended to the ellipse water entry, and the predicted maximum value of vertical force coefficient in the initial stage is 4？a/b that matches the CFD results very well, where a and b are the horizontal axis and vertical axis of the ellipse parallel and perpendicular to the initial calm water surface, respectively.

关键词： Water impact water entry fluid-structure interaction Froude number

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CO_(2)storage with enhanced gas recovery(CSEGR):A review of experimental and numerical studies

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Petroleum Science 2022年第2期19卷 594-607页

作者： Shu-Yang Liu Bo Ren Hang-Yu Li Yong-Zhi Yang Zhi-Qiang Wang Bin Wang Jian-Chun Xu ramesh agarwal Key Laboratory of Unconventional Oil&Gas Development(China University of Petroleum(East China)) Ministry of EducationQingdao266580ShandongChina School of Petroleum Engineering China University of Petroleum(East China)Qingdao266580ShandongChina Bureau of Economic Geology The Jackson School of GeosciencesThe University of Texas at AustinAustinTXUSA Research Institute of Petroleum Exploration and Development Beijing100083China Tsinghua-Berkeley Shenzhen Institute Tsinghua Shenzhen International Graduate SchoolTsinghua UniversityShenzhen518055GuangdongChina Washington University in St.Louis St.LouisMO63130USA

CO_(2)emission mitigation is one of the most critical research *** a promising option of carbon capture,utilization and storage(CCUS),CO_(2)storage with enhanced gas recovery(CSEGR)can reduce CO_(2)emission by sequestrating it into gas reservoirs and simultaneously enhance natural gas *** the past decades,the displacement behaviour of CO_(2)—natural gas has been extensively studied and demonstrated to play a key role on both CO_(2)geologic storage and gas recovery *** work thoroughly and critically reviews the experimental and numerical simulation studies of CO_(2)displacing natural gas,along with both CSEGR research and demonstration projects at various *** physical property difference between CO_(2)and natural gas,especially density and viscosity,lays the foundation of *** experiments on displacement behaviour and dispersion characteristics of CO_(2)/natural gas revealed the fundamental mixing characteristics in porous media,which is one key factor of gas recovery efficiency and warrants further *** numerical simulations demonstrated that it is technically and economically feasible to apply CSEGR in depleted gas ***,CO_(2)preferential flow pathways are easy to form(due to reservoir heterogeneity)and thus adversely compromise CSEGR *** preferential flow can be slowed down by connate or injected ***,the optimization of CO_(2)injection strategies is essential for improving gas recovery and CO_(2)storage,which needs further *** successful K12—B pilot project provides insightful field-scale knowledge and experience,which paves a good foundation for commercial *** experiments,simulations,research and demonstration projects are needed to facilitate the maturation of the CSEGR technology.

关键词： Carbon capture Utilization and storage(CCUS) Enhanced gas recovery CO_(2)geologic storage Miscible displacement Dispersion

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Generalized Boltzmann solution for non-equilibrium flows and the computation of flowfields of binary gas mixture

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Propulsion and Power Research 2012年第1期1卷 48-57页

作者： Baoguo Wang Geng Qian ramesh K.agarwal Christopher D.Wilson School of Aerospace Engineering Beijing Institute of TechnologyBeijing 100081China Department of Mechanical Engineering and Materials Science Washington UniversitySt.LouisMO 63130USA Boeing Company St.LouisMO 63166USA

Hypersonic flows about space vehicles produce flowfields in thermodynamic non-equilibrium with the local Knudsen numbers Kn which may lie in all the three regimes:continuum,transition and *** flows can be modeled accurately by solving the Navier–Stokes(NS)equations;however,the flows in transition and rarefied regimes require a kinetic approach such as the direct simulation Monte Carlo(DSMC)method or the solution of the Boltzmann *** Boltzmann equation and the general solution approach,using the splitting method,will be introduced in this *** of the method used for solving both the classical Boltzmann equation(CBE)and the generalized Boltzmann equation(GBE)are also *** gas mixture discussed in this paper may consist of both monoatomic and diatomic *** particular,the method is applied to simulate two of the three primary constituents of air(N_(2),O_(2),and Ar)in a binary mixture at 1:1 density ratio at Mach 2 and 5,with gases in translational,rotational and vibrational non-equilibrium.

关键词： Generalized Boltzmann equation Non-equilibrium flow Monoatomic gas Diatomic gas Splitting method

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Experimental Optimization of Jet Self-Priming Centrifugal Pump Based on Orthogonal Design and Grey-Correlational Method

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Journal of Thermal Science 2020年第1期29卷 241-250页

作者： CHANG Hao SHI Weidong LI Wei WANG Chuan ZHOU Ling LIU Jianrui YANG Yongfei ramesh Kagarwal Research Center of Fluid Machinery Engineering and Technology Jiangsu UniversityZhenjiang 212013China Department of Mechanical Engineering&Materials Science Washington University in St.LouisSt.Louis 63130USA School of Mechanical Engineering Nantong UniversityNantong 226019China School of Hydraulic Energy and Power Engineering Yangzhou UniversityYangzhou 225002China

The novel jet self-priming centrifugal pump,as important modern irrigation equipment,is widely used in large-scale irrigation,mine drainage and so *** order to improve the profile streamline of blade,the inlet shape of impeller was designed as distorted and the outlet shape as cylindrical,which can not only improve the pump efficiency,but also shorten the self-priming ***,the novel jet self-priming system was proposed,by employing the jet nozzle and check valve to improve the velocity of ***,nine different structure jet nozzles were designed based on the orthogonal design method,and the relevant self-priming experiments were performed on I level accuracy test bench in Jiangsu *** to the greycorrelational analysis,the influence of the nozzle geometry parameters on the self-priming performance was *** relationship between self-priming time and self-priming height was *** test results showed that the hydraulic design of jet self-priming centrifugal pump was reasonable;all indicators met the Chinese national standard;the head reached 21.04 m and efficiency was 72.8%under the design flow *** is more,the self-priming performance was obviously improved by adjusting the geometrical parameters of *** the height of the self-priming process was 5.3 m,the self-priming time reached 62 s,which was much shorter than the national ***,this research could provide reference for designing the structure of jet self-priming centrifugal pump.

关键词： self-priming centrifugal pump design optimization orthogonal experiment grey-correlational

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Clinical profile and outcomes of hepatocellular carcinoma in primary Budd-Chiari syndrome

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World Journal of Gastrointestinal Oncology 2024年第3期16卷 699-715页

作者： Ankit agarwal Sagnik Biswas Shekhar Swaroop Arnav Aggarwal Ayush agarwal Gautam Jain Anshuman Elhence Arun Vaidya Amit Gupte Ravi Mohanka ramesh Kumar Ashwani Kumar Mishra Shivanand Gamanagatti Shashi Bala Paul Subrat Kumar Acharya Akash Shukla Shalimar Department of Gastroenterology and Human Nutrition All India Institute of Medical SciencesNew Delhi 110029DelhiIndia Department of Gastroenterology Seth Gordhandas Sunderdas Medical College and KEM HospitalMumbai 400012MaharashtraIndia Department of Gastroenterology Sir HN Reliance Foundation HospitalMumbai 400004India Department of Liver Transplant and HPB Sir HN Reliance Foundation HospitalMumbai 400004India Department of Gastroenterology All India Institute of Medical SciencesPatna 801507India Professor of Biostatistics National Drug Dependence Treatment Centre(NDDTC)All India Institute of Medical SciencesNew Delhi 110029India Department of Radiodiagnosis All India Institute of Medical SciencesNew Delhi 110029DelhiIndia

BACKGROUND There is scant literature on hepatocellular carcinoma(HCC)in patients with Budd-Chiari syndrome(BCS).AIM To assess the magnitude,clinical characteristics,feasibility,and outcomes of treatment in *** A total of 904 BCS patients from New Delhi,India and 1140 from Mumbai,India were *** prevalence and incidence of HCC were determined,and among patients with BCS-HCC,the viability and outcomes of interventional therapy were *** In the New Delhi cohort of 35 BCS-HCC patients,18 had HCC at index presentation(prevalence 1.99%),and 17 developed HCC over a follow-up of 4601 person-years,[incidence 0.36(0.22-0.57)per 100 person-years].BCS-HCC patients were older when compared to patients with BCS alone(P=0.001)and had a higher proportion of inferior vena cava block,cirrhosis,and long-segment vascular *** median alpha-fetoprotein level was higher in patients with BCS-HCC at first presentation than those who developed HCC at follow-up(13029 ng/mL vs 500 ng/mL,P=0.01).Of the 35 BCS-HCC,26(74.3%)underwent radiological interventions for BCS,and 22(62.8%)patients underwent treatment for HCC[transarterial chemoembolization in 18(81.8%),oral tyrosine kinase inhibitor in 3(13.6%),and transarterial radioembolization in 1(4.5%)].The median survival among patients who underwent interventions for HCC compared with those who did not was 3.5 years vs 3.1 mo(P=0.0001).In contrast to the New Delhi cohort,the Mumbai cohort of BCS-HCC patients were predominantly males,presented with a more advanced HCC[Barcelona Clinic Liver Cancer C and D],and 2 patients underwent liver *** HCC is not uncommon in patients with *** interventions and liver transplantation are feasible in select primary BCS-HCC patients and may improve outcomes.

关键词： Budd chiari syndrome Cancer Cirrhosis Thrombosis Liver Varices Transarterial chemoembolization Hepatic venous outflow tract obstruction

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Analysis and Predictions of Spread, Recovery, and Death Caused by COVID-19 in India

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Big Data Mining and Analytics 2021年第2期4卷 65-75页

作者： Rajani Kumari Sandeep Kumar ramesh Chandra Poonia Vijander Singh Linesh Raja Vaibhav Bhatnagar Pankaj agarwal Department of Information Technology and Computer Application JECRC UniversityJaipurRajasthan 303905India Bangalore Karnataka 560029India with Amity University Rajasthan JaipurRajasthan 303002India University Jaipur Rajasthan 303007India

The novel coronavirus outbreak was first reported in late December 2019 and more than 7 million people were infected with this disease and over 0.40 million worldwide lost their lives. The first case was diagnosed on30 January 2020 in India and the figure crossed 0.24 million as of 6 June 2020. This paper presents a detailed study of recently developed forecasting models and predicts the number of confirmed, recovered, and death cases in India caused by COVID-19. The correlation coefficients and multiple linear regression applied for prediction and autocorrelation and autoregression have been used to improve the accuracy. The predicted number of cases shows a good agreement with 0.9992 R-squared score to the actual values. The finding suggests that lockdown and social distancing are two important factors that can help to suppress the increasing spread rate of COVID-19.

关键词： COVID-19 regression correlation machine learning prediction

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Post-transplant dyslipidemia: Mechanisms, diagnosis and management

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World Journal of Transplantation 2016年第1期6卷 125-134页

作者： Arnav agarwal G V ramesh Prasad Division of Nephrology Department of Medicine University of Toronto Renal Transplant Program St. Michael’s Hospital

Post-transplant dyslipidemia is highly prevalent and presents unique management challenges to the clinician. The two major outcomes to considerwith post-transplant therapies for dyslipidemia are preserving or improving allograft function, and reducing cardiovascular risk. Although there are other cardiovascular risk factors such as graft dysfunction, hypertension, and diabetes, attention to dyslipidemia is warranted because interventions for dyslipidemia have an impact on reducing cardiac events in clinical trials specific to the transplant population. Dyslipidemia is not synonymous with hyperlipidemia. Numerous mechanisms exist for the occurrence of posttransplant dyslipidemia, including those mediated by immunosuppressive drug therapy. Statin therapy has received the most attention in all solid organ transplant recipient populations, although the effect of proper dietary advice and adjuvant pharmacological and nonpharmacological agents should not be dismissed. At all stages of treatment appropriate monitoring strategies for side effects should be implemented so that the benefits from these therapies can be achieved. Clinicians have a choice when there is a conflict between various transplant society and lipid society guidelines for therapy and targets.

关键词： Cholesterol Dyslipidemia Triglycerides Statins Immunosuppression

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