scholarly journals Investigation of Complex Characteristics of Waterjet Propulsion Device with Intake Grid

2021 ◽  
Vol 2021 ◽  
pp. 1-22
Author(s):  
Can Luo ◽  
Shuaihao Lei ◽  
Chuan Wang ◽  
Li Cheng ◽  
Chenzhi Xia ◽  
...  
Keyword(s):  
Performance Index ◽  
Weighted Average ◽  
Hydraulic Performance ◽  
Hydraulic Loss ◽  
Evaluation Indexes ◽  
Flow Capacity ◽  
Pipe Segment ◽  
Negative Effect ◽  
Complex Features ◽  
Inlet Duct

The intake grid is always installed technically to protect the impeller at the entrance of the waterjet propulsion device’s inlet duct affecting its performance. Therefore, this study discussed the complex features of the circular, rectangular, and streamlined intake grid. Consistent geometry size of the intake grid mentioned above is to be maintained to guarantee the identical flow capacity at the entrance of inlet duct. Using experimental and simulated method, the outcomes are drawn as below. Rather than the circular and rectangular intake grid, the streamlined intake grid can improve the hydraulic performance of the waterjet propulsion device. The numerical method is proved to be correct as the consistence of the hydraulic characteristic between the test and simulated results. The causes of hydraulic loss in the contraction segment and straight pipe segment are the intake grid and the inflow velocity, respectively; meanwhile, the loss in the belt pipe segment owes to the vortex, flow separation, and impact on the back. The intake grid has a positive effect on the depth of the inlet velocity profile, but a negative effect on the width of it. The intake grid installation results in thrust reduction, the progress of velocity-weighted average angle, and the regress of axial velocity uniformity. The performance of waterjet propulsion device is complex and evaluated by the hydraulic performance index (HPI), thrust performance index (TPI), and characteristic of flow pattern index (CFPI). Based on the three evaluation indexes, the streamlined scheme is raised to be the recommended scheme.

scholarly journals The Influence of Bulb Position on Hydraulic Performance of Submersible Tubular Pump Device

2021 ◽  
Vol 9 (8) ◽  
pp. 831
Author(s):  
Zhuangzhuang Sun ◽  
Jie Yu ◽  
Fangping Tang
Keyword(s):  
Entropy Production ◽  
Large Scale ◽  
Experimental Testing ◽  
Guide Vane ◽  
Outer Wall ◽  
Hydraulic Performance ◽  
Hydraulic Loss ◽  
Optimized Design ◽  
Outlet Channel ◽  
Wall Area

In order to study the influence of the position of the bulb on the hydraulic performance of asubmersible tubular pump device, based on a large-scale pumping station, two schemes—involving a front-mounted bulb and a rear-mounted bulb, respectively—were designed. The front-mounted scheme uses the GL-2008-03 hydraulic model and its conventional guide vane, while the rearmounted scheme uses the optimized design of a diffuser vane. The method of combining numerical simulation and experimental testing was used to analyze the differences between the external and internal characteristics of the two schemes. The results show that, under the condition of reasonable diffusion guide vane design, the efficiency under the rear-mounted scheme is higher than that under the front-mounted scheme, where the highest efficiency difference is about 1%. Although the frontmounted bulb scheme reduces the hydraulic loss of the bulb section, the placement of the bulb on the water inlet side reduces the flow conditions of the impeller. Affected by the circulation of the guide vane outlet, the hydraulic loss of the outlet channel is greater than the rear-mounted scheme. The bulb plays a rectifying function when the bulb is placed behind, which greatly eliminates the annular volume of the guide vane outlet, and the water outlet channel has a smaller hydraulic loss. In the front-mounted scheme, the water flow inside the outlet channel squeezes to the outer wall, causing higher entropy production near the outer wall area. The entropy production of the rear-mounted scheme is mainly in the bulb section and the bulb support. This research can provide reference for the design and form selection of a submersible tubular pump device, which has great engineering significance.

scholarly journals Numerical Simulation on Hydraulic Characteristics of Nozzle in Waterjet Propulsion System

Processes ◽  
2019 ◽  
Vol 7 (12) ◽  
pp. 915 ◽  
Author(s):  
Chuan Wang ◽  
Xiaoke He ◽  
Li Cheng ◽  
Can Luo ◽  
Jing Xu ◽  
...  
Keyword(s):  
Propulsion System ◽  
Dynamics Simulation ◽  
Transition Curve ◽  
Hydraulic Loss ◽  
Main Function ◽  
System Efficiency ◽  
Hydraulic Characteristics ◽  
Linear Contraction ◽  
Circular Nozzle ◽  
Inlet Duct

As an important over-current component of the waterjet propulsion system, the main function of a nozzle is to transform the mechanical energy of the propulsion pump into the kinetic energy of the water and eject the water flow to obtain thrust. In this study, the nozzle with different geometry and parameters was simulated based on computational fluid dynamics simulation and experiment. Numerical results show a good agreement with experimental results. The results show that the nozzle with a circular shape outlet shrinks evenly. Under the designed flow rate condition, the velocity uniformity of the circular nozzle is 0.26% and 0.34% higher than that of the elliptical nozzle and the rounded rectangle nozzle, respectively. The pump efficiency of the circular nozzle is 0.31% and 0.14% higher than that of the others. The pressure recovery and hydraulic loss of the circular nozzle are superior. The hydraulic characteristics of the propulsion pump and waterjet propulsion system are optimal when the nozzle area is 30% times the outlet area of the inlet duct. Thus, the shaft power, head, thrust, and system efficiency of the propulsion pump and waterjet propulsion system are maximized. The system efficiency curve decreases rapidly when the outlet area exceeds 30% times the outlet area of the inlet duct. The transition curve forms greatly affect thrust and system efficiency. The transition of the linear contraction shows improved uniformity, and the hydraulic loss is reduced. Furthermore, the hydraulic performance of the nozzle with a linear contraction transition is better than that of others.

scholarly journals Intellectual Capital Disclosure, Information Asymmetry, Cost of Capital, and Firm Value: Empirical Studies on Indonesian Manufacturers

2019 ◽  
Vol 2 (1) ◽  
pp. 27-35
Author(s):  
Nadya Gomes I. Gomes I. ◽  
Hatane Semuel ◽  
Devie D.
Keyword(s):  
Information Asymmetry ◽  
Intellectual Capital ◽  
Firm Value ◽  
Cost Of Capital ◽  
Weighted Average ◽  
Partial Least Square ◽  
Least Square ◽  
Separate Analysis ◽  
Negative Effect ◽  
Positive Effect

Signaling theory suggests that when high-quality entities signal their potentials such as intellectual capital to the market, its participants (e.g., investors) re-evaluate their worth and make informed decisions therefrom. This paper examines the consequences of intellectual capital disclosures with respect to firm value, information asymmetry, and cost of capital. Voluntary intellectual capital disclosure (ICD, measured in index) affects firm value (FV, measured in Tobin’s Q) through reducing both information asymmetry (IA, measured in bid-ask spread) and cost of capital (COC, measured in weighted average cost of capital). 67 Indonesian manufacturers were purposively selected whose financial reports published in Indonesian Stock Exchange official website and Bloomberg provide the data for the research. A research model is estimated to the data through a partial least square analysis. Results provides substantial evidence on the positive effect of ICD on FV and negative effect on IA; negative effect of IA on FV; negative effect of COC on FV; and positive effect of IA on COC. On a separate analysis, IA is shown to significantly mediate the relationship between ICD and FV.

scholarly journals PENGARUH INTELLECTUAL CAPITAL DAN RATA – RATA PERTUMBUHANNYA (ROGIC) TERHADAP KINERJA BANK SYARIAH BERDASARKAN ISLAMICITY PERFORMANCE INDEX DI INDONESIA

2021 ◽  
Vol 16 (1) ◽  
pp. 54-68
Author(s):  
Sasiska Rani ◽  
Martha Rianty N
Keyword(s):  
Regression Analysis ◽  
Data Analysis ◽  
Intellectual Capital ◽  
Performance Index ◽  
Sampling Technique ◽  
Profit Sharing ◽  
Average Growth ◽  
Analysis Techniques ◽  
Negative Effect ◽  
Positive Effect

This study examines the effect of intellectual capital and the average growth intellectual capital (ROGIC) on the performance of Syariah Banks based on the Islamicity Performance Index in Indonesia. The Islamicity Performance Index in this study is proxied by the Profit Sharing Ratio (PSR). The sample obtained was based on the purposive sampling technique in this study, namely 10 Syairah Banks from 2015 - 2019. This study used data analysis techniques in the form of multiple regression analysis. The results show that there is a negative effect between intellectual capital on the Islamicity Performance Index, which is proxied by the Profit Sharing Ratio (PSR). The average growth of intellectual capital (ROGIC) has a positive effect on the Islamicity Performance Index, which is proxied by the Profit Sharing Ratio (PSR).

Research on Flexibility Evaluation of Microgrid System with Energy Storage

2021 ◽  
Vol 14 ◽  
Author(s):  
Tao Shi ◽  
Xuezheng Si ◽  
Zhaohui Li
Keyword(s):  
Energy Storage ◽  
Distribution Network ◽  
Maximum Energy ◽  
Operational Flexibility ◽  
Evaluation Indexes ◽  
The Public ◽  
Power Regulation ◽  
Negative Effect ◽  
Integration Mode ◽  
Operation Cycle

Background: Microgrid is an effective integration mode of distributed generation (DG). It can eliminate the negative effect caused by the intermittent DG and consume the energy locally. Methods: For a public distribution network, a microgrid performs as a controllable and flexible unit. However, when the public distribution network has the demand of flexible regulation, there is no reasonable quantitative indexes to evaluate the flexibility of microgrid for dispatching decision. For this problem, the operational flexibility indexes of a microgrid are defined in this paper. Results: The indexes are quantified according to the maximum energy and active power regulation margin of each flexible equipment in the microgrid. The operational flexibility of microgrid is closely related to the scheduling strategy. Therefore the corresponding dispatching model of a microgrid is also provided in this paper. Conclusion: Then a case study shows how to calculate and use these flexibility indexes in an operation cycle of a microgrid system with energy storage (ES) facility and demonstrate the availability and practicability of the evaluation indexes and the method.

Thermal and Hydraulic Performance of Counterflow Microchannel Heat Exchangers With and Without Nanofluids

2011 ◽  
Vol 133 (8) ◽  
Author(s):  
Hamid Reza Seyf ◽  
Shahabeddin Keshavarz Mohammadian
Keyword(s):  
Reynolds Number ◽  
Brownian Motion ◽  
Performance Index ◽  
Volume Fraction ◽  
Reynolds Numbers ◽  
Hydraulic Performance ◽  
Working Fluid ◽  
Pumping Power ◽  
Mean Diameter ◽  
And Performance

Abstract This paper analyzes the thermal and hydraulic performance of a counterflow microchannel heat exchanger (CFMCHE) with and without nanofluid as working fluid. A 3D conjugate heat transfer simulation is carried out using a finite volume approach to evaluate the effects of inlet Reynolds number, Brownian motion, and volume fraction of nanoparticles on the pumping power, effectiveness, and performance index of CFMCHE. The accuracy of the code has been verified by comparing the results with those available in the literature. A single phase approach is used for the nanofluid modeling. The base fluid used in the analyses as a basis for comparison was pure water. Two types of nanofluids, namely, water-Al2O3 with a mean diameter of 47 nm and water-CuO with a mean diameter of 29 nm, each one with three different volume fractions, are utilized. In addition, two temperature dependent models for the thermal conductivity and viscosity of nanofluids that account for the fundamental role of Brownian motion are used. Calculated results demonstrate that the effectiveness and performance index of CFMCHE decrease with increasing Reynolds number. Moreover, it is observed that the relative enhancements in the pumping power become more prominent for higher values of Reynolds numbers. It was also found that the performance index and pumping power are not sensitive to volume fraction at higher and lower Reynolds numbers, respectively.

scholarly journals MEKANISME ISLAMIC CORPORATE GOVERNANCE PADA KINERJA BANK UMUM SYARIAH MENGGUNAKAN ISLAMIC PERFORMANCE INDEX

2019 ◽  
Vol 4 (2) ◽  
Author(s):  
Oktaviani Rita Puspasari
Keyword(s):  
Corporate Governance ◽  
Performance Index ◽  
Audit Committee ◽  
Supervisory Board ◽  
Independent Directors ◽  
Bank Performance ◽  
Committee Meeting ◽  
Islamic Bank ◽  
Negative Effect ◽  
Positive Effect

This study examine how Islamic Corporate Governance mechanism which are : a number of sharia supervisory board meeting, independent directors, a number of audit committee meeting has an effect to the Islamic Bank performance in Indonesia which meassured by Islamic Performance Index, which proxy by : Profit sharing ratio (PSR), Islamic Income Ratio (IIR) and Equitable Distribution Ratio (EDR).� The sample selection method is purposive sampling and obtained 9 Islamic bank in 5 years period observation with 45 data are being sampled.� Multiple regression analysis is used to analyze the data.� The results shows that a number of DPS meeting have a negative effect �to PSR&EDR, however positive effect showed for IIR.� Then, independent directors have a negative effect to the PSR and IIR, however it has positive effect for EDR. As well as, negative effect showed by a number of audit committee meeting to PSR and IIR, while a number of audit committee meeting have positive effect for EDR. However the analysis result show that there are no significant effect from independent variable to the Islamic Bank performance which measured by Islamic Performance Index.Keyword:� A number of Sharia Supervisory Board meetings, Independent Directors, a number of audit committee meeting, Islamic Bank Performance.

scholarly journals Pengaruh Biaya Modal dan Profitabilitas Terhadap Nilai Saham Bank BTPN Syariah Periode 2018-2020

Owner ◽  
2022 ◽  
Vol 6 (1) ◽  
pp. 298-307
Author(s):  
Siska Yuli Anita
Keyword(s):  
Quantitative Research ◽  
Cost Of Capital ◽  
Weighted Average ◽  
Secondary Data ◽  
Return On Equity ◽  
Stock Value ◽  
Negative Effect ◽  
The Cost ◽  
Corporate Profits ◽  
Stock Values

Operations and investments of Islamic banks certainly require capital as the foundation and start of the bank's business, so estimating the cost of capital required is an important process and good corporate profits will provide a good image for the company. This study aims to determine the effect of capital with the Weighted Average Cost Of Capital (WACC) method on stock values. The effect of profitability with the ratio of Return On Equity (ROE) on stock value. And the effect of the cost of capital and profitability on the value of the stock. This study uses a descriptive quantitative research method. By using secondary data in the form of monthly financial statements of Bank BTPN Syariah for the 2018-2020 period. All of these data are materials for estimating and calculating the cost of capital and profitability of Bank BTPN Syariah. The results showed that partially the cost of capital had a significant positive effect on the stock value, profitability had a significant negative effect on the stock value. Meanwhile, simultaneously the cost of capital and profitability affect the value of the stock.

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