Instantaneous flow rates

1998 ◽  
pp. 30-39
Keyword(s):  
Flow Rates ◽  
Instantaneous Flow

Measurement of instantaneous flow rates in periodically operating injection systems

1996 ◽  
Vol 20 (3) ◽  
pp. 178-188 ◽  
Author(s):  
F. Durst ◽  
M. Ismailov ◽  
D. Trimis
Keyword(s):  
Flow Rates ◽  
Instantaneous Flow

Four-port hydraulic transformer with inlet and outlet equal flow and its flow characteristics

2021 ◽  
pp. 095440622110316
Author(s):  
Chu Zhang ◽  
Lianquan Zhou ◽  
Xiaonan Bo ◽  
Weiwei Qu ◽  
Panpan Zang
Keyword(s):  
Theoretical Analysis ◽  
Flow Rate ◽  
Hydraulic System ◽  
Measurement Data ◽  
Flow Characteristics ◽  
Remarkable Feature ◽  
Flow Rates ◽  
Instantaneous Flow ◽  
Hydraulic Transformer ◽  
System A

Without changing the original valve control hydraulic system, a kind of hydraulic transformer, called four-port hydraulic transformer (FHT), is proposed to recover the energy loss caused by system throttling. The remarkable feature of FHT is that the flow rate at inlet and outlet ports are equal. This means that FHT can be connected into the load circuit of hydraulic system to recovery energy without refreshing flow rate. This paper investigates the flow characteristics of FHT, including instantaneous flow rates, average flow rates and flow pulsations in each port. The relationships between the structure of port plate and the flow characteristics are given. The variation rule of number of plungers connected to four ports is shown, and the relationship between the variation and the flow pulsation is revealed. The simulation results show that the flow rates and displacements of symmetrical ports are same, and the instantaneous flow rate of symmetrical ports has the same rule. The results also show the frequent changes of the number of plungers connected with each port lead to more flow jump points in instantaneous curves, and the jump point is the basic cause of its loud noise. The test shows that the flow rates of measurement data of the experiment are very close to the theoretical analysis, proved the theoretical analysis of flow characteristics for FHT are appropriate and reasonable, which has a certain reference for the development and energy-saving application for FHT.

Instantaneous Flow Rate Measurement of Ideal Gases

1996 ◽  
Vol 122 (1) ◽  
pp. 174-178 ◽  
Author(s):  
Kenji Kawashima ◽  
Toshiharu Kagawa ◽  
Toshinori Fujita
Keyword(s):  
Heat Transfer ◽  
Flow Rate ◽  
Isothermal Condition ◽  
Flow Rate Measurement ◽  
Steel Wool ◽  
Simple Method ◽  
Flow Rates ◽  
Instantaneous Flow ◽  
Ideal Gases ◽  
Instantaneous Flow Rate

In this paper, a chamber called an “Isothermal Chamber” was developed. The isothermal chamber can almost realize isothermal condition due to larger heat transfer area and heat transfer coefficient by stuffing steel wool in it. Using this chamber, a simple method to measure flow rates of ideal gases was developed. As the process during charge or discharge is almost isothermal, instantaneous flow rates charged into or discharged from the chamber can be obtained measuring only pressure in the chamber. The steady and the unsteady flow rate of air were measured by the proposed method, and the effectiveness of the method was demonstrated. [S0022-0434(00)00301-4]

Non-Steady Characteristics of a Pneumatic Servo-Valve

1973 ◽  
Vol 15 (1) ◽  
pp. 76-78 ◽  
Author(s):  
G. Dent ◽  
A. J. Reynolds
Keyword(s):  
Flow Pattern ◽  
Internal Flow ◽  
Flow Rates ◽  
Servo Valve ◽  
Instantaneous Flow ◽  
Valve Opening

Measurements of the instantaneous flow rates through a pneumatic servo-valve are presented for valve opening frequencies between 0 and 10 Hz. While the correlation of the results is broadly consistent with the hypothesis that the internal flow pattern is independent of frequency, there is some evidence that switching between alternative patterns may occur at some frequencies.

scholarly journals An in-vitro model of stiffened aortic valves to develop an iso-stiffness-lines graph for severity evaluation aortic stenosis

2021 ◽  
Vol 42 (Supplement_1) ◽  
Author(s):  
E Buffle ◽  
M Stucki ◽  
D Obrist ◽  
S F De Marchi
Keyword(s):  
Aortic Valve ◽  
Aortic Stenosis ◽  
Time Lag ◽  
Left Ventricular ◽  
Public Institution ◽  
Low Flow ◽  
Sigmoid Function ◽  
Mean Flow ◽  
Flow Rates ◽  
Instantaneous Flow

Abstract Introduction The echocardiographic diagnosis of aortic stenosis (AS) is established by assessing its maximal opening area (OA). The behavior of OA is dependent on transvalvular flow which can be low in case of low-flow, low-gradient AS. However, current guidelines for the assessment of AS do not consider flow but rather a stroke volume. This experiment was designed to create a graphical representation of the OA versus flow for various valve stiffness values to eventually build a model with iso-stiffness lines. Methods We filmed harvested porcine aortic valve mounted in a pulsatile flow loop during the ejection time with a high speed camera (2000Hz), measured for each time point OA and the instantaneous flow through the aortic valve at 10 different mean flow rates (ranging from 0.5 to 5.0 liters/min) and divided both, OA and flow, by the area of left ventricular outflow tract (LVOT) in order to account for different valve sizes. We plotted each OA against its corresponding flow after correcting for the intersignal delay. Due to a time lag between flow onset and the valve opening caused by a ballooning of the valve, we only included the points corresponding to the 5% highest instantaneous flow rates (for each of the 10 mean flow rates). We stiffened the valve by treating it with a protein cross-linking agent (formaldehyde) to yield a total of three stiffness grades (a, b, c) and repeated the procedure for each of those grades. Results We generally observed an asymptotic appearance of the flow-OA relationship as well as a flattening of this relationship with increasing valve stiffening. This visually matches well simulated data generated with a sigmoid model. Conclusions We could obtain all flow/OA pairs at different stiffness grades. This will allow us to fit a sigmoid function capturing the flow-OA relationship for each stiffness grade and create iso-stiffness line that will allow classifying valve stenosis grade irrespective of the flow and the size of the valve in one single graph, potentially simplifying the grading system of aortic stenosis, especially for patient with low-flow, low-gradient AS. FUNDunding Acknowledgement Type of funding sources: Public Institution(s). Main funding source(s): Bern Center for Precision Medicine (BCPM) Stiffness stage 1 All stiffness stages combined

Automation of Process Control in Chemical Plant

2015 ◽  
Vol 2 (1) ◽  
pp. 6-12
Author(s):  
Agus Sugiarta ◽  
Houtman P. Siregar ◽  
Dedy Loebis
Keyword(s):  
Process Control ◽  
Pid Control ◽  
Control Algorithm ◽  
Chemical Engineering ◽  
Chemical Plant ◽  
Raw Material ◽  
Flow Rates ◽  
Material Supply ◽  
Wide Range ◽  
Inherent Problem

Automation of process control in chemical plant is an inspiring application field of mechatronicengineering. In order to understand the complexity of the automation and its application requireknowledges of chemical engineering, mechatronic and other numerous interconnected studies.The background of this paper is an inherent problem of overheating due to lack of level controlsystem. The objective of this research is to control the dynamic process of desired level more tightlywhich is able to stabilize raw material supply into the chemical plant system.The chemical plant is operated within a wide range of feed compositions and flow rates whichmake the process control become difficult. This research uses modelling for efficiency reason andanalyzes the model by PID control algorithm along with its simulations by using Matlab.

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