Hydraulic characteristics of multi-stage orifice plate

2014 ◽  
Vol 19 (3) ◽  
pp. 361-366 ◽  
Author(s):  
Wan-zheng Ai ◽  
Qi Zhou
Keyword(s):  
Orifice Plate ◽  
Hydraulic Characteristics ◽  
Multi Stage

Experimental and Numerical Study of Hydrodynamic Cavitation of Orifice Plates with Multiple Triangular Holes

2012 ◽  
Vol 256-259 ◽  
pp. 2519-2522 ◽  
Author(s):  
Zhi Yong Dong ◽  
Qi Qi Chen ◽  
Yong Gang Yang ◽  
Bin Shi
Keyword(s):  
Velocity Profile ◽  
High Speed ◽  
Numerical Study ◽  
Three Dimensional ◽  
Flow Characteristics ◽  
Orifice Plate ◽  
Hydrodynamic Cavitation ◽  
High Speed Photography ◽  
Hydraulic Characteristics ◽  
Image Velocimetry

Hydraulic characteristics of orifice plates with multiple triangular holes in hydrodynamic cavitation reactor were experimentally investigated by use of three dimensional particle image velocimetry (PIV), high speed photography, electronic multi-pressure scanivalve and pressure data acquisition system, and numerically simulated by CFD software Flow 3D in this paper. Effects of number, arrangement and ratio of holes on hydraulic characteristics of the orifice plates were considered. Effects of arrangement and ratio of holes and flow velocity ahead of plate on cavitation number and velocity profile were compared. Distribution of turbulent kinetic energy and similarity of velocity profile were analyzed. And characteristics of cavitating flow downstream of the orifice plate were photographically observed by high speed camera. Also, a comparison with flow characteristics of orifice plate with hybrid holes (circle, square and triangle) was made.

scholarly journals Evaporation characteristics and efficient working area of multi-stage high pressure and temperature reducing valve

2021 ◽  
pp. 162-162
Author(s):  
Li-Hua Cao ◽  
He-Yong Si ◽  
En-Fu Dong ◽  
Zhan-Zhou Wang ◽  
Huan-Huan Luo ◽  
...  
Keyword(s):  
High Pressure ◽  
Total Pressure ◽  
Thermal Process ◽  
Flow Model ◽  
Flow Characteristics ◽  
Water Layer ◽  
Orifice Plate ◽  
High Pressure And Temperature ◽  
Multi Stage ◽  
Increase Rate

A well understanding on the evaporation characteristics and efficient working area of MSHPTRV (multi-stage high pressure and temperature reducing valve) is important for improving the performance and safety of MSHPTRV. The water spraying and evaporation model are integrated into the flow model of MSHPTRV. Compared with the experimental data, the model can show the thermal process well. The flow characteristics and interaction between steam and droplets are presented. On this basis, the increase rate of entropy Sdis is adopted to analyze the thermodynamic loss and innovatively determine the efficient working area of MSHPTRV. The results show that the pressure reducing effect of the second orifice plate is prominent, which accounts for 41.6% of the total pressure drop. The "steam-water layer" is formed at the boundary of steam and water. At the inlet of second orifice plate, the maximum Sdis is 0.782, and the downstream of second orifice plate is the efficient working area of MSHPTRV. The length of evaporation section increases with the droplets diameter significantly.

Review on the Research of Orifice Plate Hydraulic Characteristics

2014 ◽  
Vol 590 ◽  
pp. 101-104
Author(s):  
Jia Hong Wang ◽  
Wan Zheng Ai
Keyword(s):  
Energy Loss ◽  
Orifice Plate ◽  
Effective Energy ◽  
Hydraulic Characteristics ◽  
Energy Dissipater

Orifice plate energy dissipater, as a kind of effective energy dissipater with characteristics of economic, has become welcomed more and more by hydraulics researchers. Although many researches have been conducted on orifice plate’s hydraulic characteristics, there are many other issues, which are closely related with orifice plate’s energy loss and cavitations, needed to be solved. Some issues on orifice plate’s hydraulic characteristics have been put forward in this paper so as to strengthen research in this field.

Numerical Simulations on Throttle Characteristic With Large Pressure Drop and Optimal Design of the Orifice Plate

2018 ◽  
Author(s):  
Hu Chen ◽  
Wang Jue ◽  
Wang Cong ◽  
Gong Zili ◽  
Jia Zhen ◽  
...  
Keyword(s):  
Pressure Drop ◽  
Flow Velocity ◽  
Eddy Current ◽  
Low Frequency ◽  
Orifice Plate ◽  
Optimized Design ◽  
Multi Stage ◽  
Low Frequency Vibration ◽  
Large Pressure ◽  
Large Flow

The orifice throttle pipelines with large pressure drop suffer damages from two aspects: high frequency vibration caused by cavitation and low frequency vibration caused by high flow velocity. In order to solve the vibration phenomenon of typical throttling pipe with large pressure drop in the system of nuclear power plant, the key hydraulic characteristics such as pressure drop, flow velocity, streamline and eddy current were simulated and analyzed for single-stage orifice throttling pipe. The negative pressure area was found in the downstream of the orifice, where cavitation occurred. Eddy current was formed due to the large local velocity caused by the orifice plate jet. Then, the throttle performance of multi-stage concentric orifice plates was evaluated by means of blockage pressure drop method. The cavitation damage was relieved greatly. But it was not eliminated, especially in the last stage orifice. The expanding type five-stage orifice plate was designed according to pressure drop stage-decreasing principle, with which the possibility of cavitation was eliminated but large pressure drop resulted in large flow velocity at the downstream of the first orifice plate. Multi-stage eccentric orifice plate was designed with the consideration both in cavitation characteristics and velocity distribution, which could eliminate the harm of cavitation and reduce the low frequency vibration caused by large flow velocity to a maximum extent. As a result, multistage eccentric orifice plates could be recommended as an optimized design scheme for the vibration control of the orifice piping with large pressure drop.

Planning and Search in Multi-Stage Risky Decision Making

2011 ◽  
Author(s):  
Jared Hotaling ◽  
Jerry Busemeyer ◽  
Richard Shiffrin
Keyword(s):  
Decision Making ◽  
Risky Decision Making ◽  
Risky Decision ◽  
Multi Stage

Effects of Cooking Oil Subsidy Removals on Related Markets in Malaysia: A Comparative Static, Multicommodity, Multi Stage Production Approach

2011 ◽  
Author(s):  
Jamal Othman ◽  
Yaghoob Jafari
Keyword(s):  
Equilibrium Model ◽  
Comparative Statics ◽  
Partial Equilibrium ◽  
Cooking Oil ◽  
Multi Stage ◽  
Supply Factor ◽  
Partial Equilibrium Model ◽  
Factor Markets ◽  
Input Markets ◽  
Production Approach

Malaysia is contemplating removal of most of her subsidy support measures including subsidies on cooking oil which is largely palm oil based. This paper aims to examine the effects of cooking oil subsidy removals on the competitiveness of the oil palm subsector and related markets. This is done by developing and applying a comparative static, multi-commodity, partial equilibrium model with multi-stages of production function for the Malaysian perennial crops subsector which explicitly links different stages of production, primary and intermediate input markets, trade, and policy linkages. Results partly suggest that export of cooking oil will increase by 0.2 per cent due to a 10 per cent cooking oil subsidy reduction, while domestic output of cooking oil may eventually see a net decline of 1.97 per cent. The results clearly point out that the effect of reducing cooking oil subsidies is relatively small at the upstream levels and therefore it only induces minute effects on factor markets. Consequently, the market for other agricultural crops is projected to change very marginally.   Keywords: Multicomodity, comparative statics, partial equilibrium model, output supply-factor markets linkages, effects of cooking oil subsidy removals.

IMPACT ASSESSMENT OF AGRICULTURAL TRANSFORMATION PROJECT ON PRODUCTIVITY AND POVERTY AMONG RICE FARMERS IN KANO STATE, NIGERIA.

2020 ◽  
Vol 4 (2) ◽  
pp. 392-400
Author(s):  
O. S. Balogun ◽  
M. A. Damisa ◽  
O. Yusuf ◽  
O. L. Balogun
Keyword(s):  
Sampling Method ◽  
Insect Pests ◽  
Study Data ◽  
Average Treatment Effect ◽  
Descriptive Statistics ◽  
Rice Farmers ◽  
Agricultural Transformation ◽  
Multi Stage ◽  
Significant Difference ◽  
Late Model

The study was carried out to examine the effect of agricultural transformation on the beneficiary’s productivity and poverty of rice farmers in Kano State Nigeria. A multi-stage sampling method was employed to select 571 respondents for the study. Data were collected through structured questionnaires on respondent’s income, input and output quantities as well as their expenditures. Data were analysis using descriptive statistics, Foster-Greer-Thorbecke (FGT), Propensity score matching and LATE model. Results from the study shows that respondents productivity revealed a significant difference of about 127 kg/ha in rice productivity between participants and non-participants. Also, the LATE estimates revealed an average treatment effect ATE0 of about 222.98kg/ha. Furthermore, the project had a significant effect N11, 321.4 on the participant’s consumption expenditure than the non-participants N9980.60. Moreover, participants were, able to increase their household total expenditures by N34780 per annum. Fluctuations of input/output prices insect pests and inadequate extension visits were all the major constraints faced by the farmers. It was recommended that farmers’ information and sensitization system should be overhauled and improved. Also, attention should be given to well organize extension visits for the farmers from stake holders

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