Shape optimisation for the improved performance of a novel bi-directional flow rate measuring device: Olive-shaped flowmeter (OSF)

Measurement ◽  
2021 ◽  
pp. 110614
Author(s):  
Guozeng Feng ◽  
Xinxin Gu ◽  
Dachuan Shi ◽  
Yuejiao Guo
Keyword(s):  
Flow Rate ◽  
Shape Optimisation ◽  
Measuring Device ◽  
Directional Flow ◽  
Improved Performance

Identification of Wake Convection and Flow Outline in the Interface Region of Blade Rows With Axial Gap in a Counter Rotating Turbine

2019 ◽  
Author(s):  
Rayapati Subbarao ◽  
M. Govardhan
Keyword(s):  
Flow Pattern ◽  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Three Dimensional ◽  
Interface Region ◽  
Turbine Stage ◽  
Deviation Angle ◽  
Flow Rates ◽  
Improved Performance

Abstract In a Counter Rotating Turbine (CRT), the stationary nozzle is trailed by two rotors that rotate in the opposite direction to each other. Flow in a CRT stage is multifaceted and more three dimensional, especially, in the gap between nozzle and rotor 1 as well as rotor 1 and rotor 2. By varying this gap between the blade rows, the flow and wake pattern can be changed favorably and may lead to improved performance. Present work analyzes the aspect of change in flow field through the interface, especially the wake pattern and deviation in flow with change in spacing. The components of turbine stage are modeled for different gaps between the components using ANSYS® ICEM CFD 14.0. Normalized flow rates ranging from 0.091 to 0.137 are used. The 15, 30, 50 and 70% of the average axial chords are taken as axial gaps in the present analysis. CFX 14.0 is used for simulation. At nozzle inlet, stagnation pressure boundary condition is used. At the turbine stage or rotor 2 outlet, mass flow rate is specified. Pressure distribution contours at the outlets of the blade rows describe the flow pattern clearly in the interface region. Wake strength at nozzle outlet is more for the lowest gap. At rotor 1 outlet, it is less for x/a = 0.3 and increases with gap. Incidence angles at the inlets of rotors are less for the smaller gaps. Deviation angle at the outlet of rotor 1 is also considered, as rotor 1-rotor 2 interaction is more significant in CRT. Deviation angle at rotor 1 outlet is minimum for this gap. Also, for the intermediate mass flow rate of 0.108, x/a = 0.3 is giving more stage performance. This suggests that at certain axial gap, there is better wake convection and flow outline, when compared to other gap cases. Further, it is identified that for the axial gap of x/a = 0.3 and the mean mass flow rate of 0.108, the performance of CRT is maximum. It is clear that the flow pattern at the interface is changing the incidence and deviation with change in axial gap and flow rate. This study is useful for the gas turbine community to identify the flow rates and gaps at which any CRT stage would perform better.

Rotor Design and Optimization in Internal Lobe Pumps

1997 ◽  
Vol 50 (11S) ◽  
pp. S133-S141 ◽  
Author(s):  
Giovanni Mimmi ◽  
Paolo Pennacchi
Keyword(s):  
Flow Rate ◽  
Performance Comparison ◽  
Definite Function ◽  
Pump Design ◽  
Design And Optimization ◽  
Performance Indexes ◽  
New Type ◽  
Improved Performance ◽  
Lobe Pump ◽  
Rotor Curvature

The topic of this paper is the design of internal lobe pumps and their optimization which is based on specific performance indexes. Internal lobe pumps can be classified as different types depending on the shape of the lobe of the outer rotor. First, the design of internal lobe pumps with elliptical, sinusoidal, and polycircular lobe profiles is considered. The latter is a new type of lobe profile with special shape whose curvature follows a definite function. Then we introduce the performance indexes used for the comparison. Some of these indexes, such as the flow rate irregularity, are commonly used for performance comparison, while others, such as the specific slipping and the rotor curvature, are particularly suitable in this case. The comparisons are made with the circular type that had been analyzed by the authors in previous papers (see eg, Mimmi, Pannacchi, and Savi (1996), Internal Lobe Pump Design, Mechanics in design - Proc CSME Forum ’96, SA Meguid (ed), Toronto, Ontario, Canada). It is not easy to univocally state the superiority of one type with respect to the others, however, it is possible to notice that elliptical and polycircular types are comparable to the circular ones in terms of flow rate irregularity, but have improved performance in terms of specific slipping and rotor curvature.

Goal Driven Shape Optimisation for Conjugate Heat Transfer in an Effusion Cooling Plate

2015 ◽  
Author(s):  
W. Savastano ◽  
A. Pranzitelli ◽  
G. E. Andrews ◽  
M. E. Biancolini ◽  
D. B. Ingham ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Flow Rate ◽  
Conjugate Heat Transfer ◽  
Coolant Flow ◽  
Geometrical Parameters ◽  
Shape Optimisation ◽  
Local Cooling ◽  
Ansys Fluent ◽  
Cooling Effectiveness ◽  
Square Array

Full coverage effusion cooling was numerically investigated by means of conjugate heat transfer (CHT) computational fluid dynamics (CFD) for an array of effusion cooling holes in order to maximise the overall cooling effectiveness for a fixed coolant mass flow rate G, kg/sm2. The baseline case study consisted of a 152×152×6.35mm perforated wall with a 300 K, 0.18 kg/sm2 coolant flow through a square array of 90° effusion holes. The plate was mounted in a 770 K duct crossflow. The numerical model was validated against the experimental work of Andrews et al. (1990) and showed a maximum disagreement between the prediction and the experimental data of 3%. The effects of three geometrical parameters, i.e. the inclination of the holes, the pitch in X direction and the pitch in Y direction, on the overall cooling effectiveness were investigated without varying the coolant flow rate. The inclination of the effusion holes was varied between −33° and +33° from the plane of the plate, while the pitch in both directions was varied between 10.64mm and 19.76mm. The numerical investigation was performed using the commercial software ANSYS Workbench following a design of experiments approach. The geometrical modifications were obtained automatically in the CFD solver ANSYS Fluent for each design point by means of the RBF Morph software. This avoided the manual modification of the geometry and the subsequent mesh generation. The optimised configuration was obtained considering the maximisation of the average overall cooling effectiveness as a goal and a chosen minimum value for the local cooling effectiveness of 0.4 as the constraint. The results showed that the inclination of the effusion holes and the pitch in the Y direction have a greater impact on the cooling effectiveness than the pitch in the X direction, up to 17%, 28% and 5% from the baseline, respectively, within the range of values considered. An optimal combination of the three parameters was determined.

A New Intermittent Aspirated Probe for the Measurement of Stagnation Quantities in High Temperature Gases

2011 ◽  
Vol 133 (4) ◽  
Author(s):  
Michela Massini ◽  
Robert J. Miller ◽  
Howard P. Hodson
Keyword(s):  
High Temperature ◽  
Mass Flow ◽  
Flow Rate ◽  
Stagnation Pressure ◽  
Stagnation Temperature ◽  
Measuring Device ◽  
Second Mode ◽  
Total Temperature ◽  
Flow Through ◽  
Temperature And Pressure

This paper presents the design, manufacture, and testing of a new probe for the measurement of temperature and pressure in engine environments. The probe consists of a choked nozzle located in the flow and a system downstream including a cooler, a flow measuring device, and a valve. It operates in two modes: In the first mode the valve is open, the probe is aspirated, and the nozzle is choked. The mass flow through the probe is measured using instrumentation placed downstream of the cooler, so that it does not have contact with the hot flow. In the second mode, the valve is closed, and the stagnation pressure is measured using the same instrumentation downstream the cooler. The total temperature is computed as a derived variable from the measurements of stagnation pressure and mass flow rate. There are a number of advantages of the probe over existing methods of temperature measurement. The measurement inaccuracy due to conduction and radiation errors and calibration drift found in thermocouples is significantly reduced; it can measure both stagnation temperature and pressure, halving the instrumentation costs; it has no wiring or transducer in the sensor head; the system can self-calibrate while located within an engine. This paper describes the design of a probe for use in engine environments. The probe prototype is tested up to 900 K and is shown to have an accuracy of ±6 K.

scholarly journals Understanding the Effect of Stepwise Irrigation on Liquid Holdup and Hysteresis Behavior of Unsaturated Ore Heap

Minerals ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1180
Author(s):  
Leiming Wang ◽  
Shenghua Yin ◽  
Bona Deng
Keyword(s):  
Flow Rate ◽  
Packed Bed ◽  
Critical Issue ◽  
Low Grade ◽  
Residual Liquid ◽  
Liquid Holdup ◽  
Measuring Device ◽  
Hysteresis Behavior ◽  
Liquid Retention ◽  
Relative Porosity

Liquid is a crucial medium to contain soluble oxygen, valuable metal ions, and bacteria in unsaturated heap leaching. Liquid retention behavior is the first critical issue to be considered to efficiently extract low-grade minerals or wastes. In this study, the residual liquid holdup of an unsaturated packed bed was quantitatively discussed by liquid holdup (θ), residual liquid holdup (θresidual), relative liquid holdup (θ’), and relative porosity (n*) using the designed measuring device. The detailed liquid holdup and the hysteresis behavior under stepwise irrigation are indicated and discussed herein. The results show that relative porosity of the packed bed was negatively related to particle size, and intra-particle porosity was more developed in the −4.0 + 2.0 mm packed bed. The higher liquid retention of the unsaturated packed bed could be obtained by using stepwise irrigation (incrementally improved from 0.001 to 0.1 mm/s) instead of uniform irrigation (0.1 mm/s). It could be explained in that some of the immobile liquid could not flow out of the unsaturated packed bed, and this historical irrigation could have accelerated formation of flow paths. The θ was sensitive to superficial flow rate (or irrigation rate) in that it obviously increased if a higher superficial flow rate (u) was introduced, however, the θresidual was commonly affected by n* and θ’. Moreover, the liquid hysteresis easily performed under stepwise irrigation condition, where θ and θresidual were larger at u of the decreasing flow rate stage (DFRS) instead of u of the increasing flow rate stage (IFRS). These findings effectively quantify the liquid retention and the hysteresis behavior of ore heap, and the stepwise irrigation provides potential possibility to adjust liquid retention conditions.

scholarly journals Working Principle of Gas Turbine Meter Fluxi 2000/TZ and Gas Volume Converter

2020 ◽  
Vol 4 (8) ◽  
pp. 90-93
Keyword(s):  
Natural Gas ◽  
Gas Turbine ◽  
Flow Rate ◽  
Gas Flow ◽  
Flow Meter ◽  
Measuring Device ◽  
Flow Meters ◽  
Working Principle ◽  
Flow Through ◽  
Gas Volume

The use of natural gas in several countries, especially in Indonesia is essential. In gas distribution, every industry and household will not be separated from the measurement system that aims to find out how much natural gas has been used. For this reason, the use of a gas flow meter is necessary. There are several types of gas flow meter can be used in measuring the gas volume. Some types of gas flow meters are gas turbine meters, rotary gas meters and diaphragm gas meters. The primary difference of each type of gas flow meter is the pressure capacity and the speed of the gas flow through it. Flow meter gas turbine is one type of gas flow rate measuring device. There are moving parts consisting of a propeller whose rotation speed is proportional to the flow rate through the flow meter. The type of gas turbine meter is Fluxi 2000/TZ. Fluxi 2000/TZ is designed to measure natural gas and various non-corrosive gases. This tool can be used to measure low gas flow and high gas flow. This tool can also be used to measure flow under various pressure conditions. Corus is the name of the type of gas volume converter. Corus is one instrument that supports the reading process of various gas meters, and one of them is a gas turbine meter. Corus is designed to achieve high levels of performance and accuracy from robust electronic equipment so that the results of reading the fluid volume available on the gas turbine meter can be calculated more accurately regard to the amount of temperature, pressure and compressibility. The working principle and characteristics of the two instruments make the measurements more accurate.

Effect of Bubble Size and Angle of Tapered Upriser Pipe on the Effectiveness of a Two Phase Lifting Pump

2009 ◽  
Author(s):  
P. Hanafizadeh ◽  
M. H. Saidi ◽  
A. Zamiri ◽  
A. Karimi
Keyword(s):  
Gas Phase ◽  
Flow Rate ◽  
Bubble Size ◽  
Gas Flow ◽  
Bubble Diameter ◽  
Design Parameters ◽  
Two Phase ◽  
Bubble Distribution ◽  
Improved Performance ◽  
Different Diameters

Two phase lifting pumps are devices with the ability of lifting liquid phase by injecting the gas phase. Parameters which affect the performance of these pumps are divided into two groups. The first group contains design parameters such as diameter of the pipe, tapering angle of the upriser pipe and the submergence ratio which is the ratio of immersed length to the total length of the upriser. The second group includes operating parameters, such as the gas flow rate, bubble diameter, bubble distribution and inlet gas pressure. In this research, the performance of two phase lifting pump is investigated numerically for different submergence ratios and different diameter of the upriser pipe. For this purpose the two phase pump with a riser length of 914 mm and different diameters (6, 8 and 10 mm), and seven tapering angles (0°, 0.25°, 0.5°, 1°, 1.5°, 2° and 3°) are numerically modeled and analyzed. Different submergence ratios are used, namely: 0.4, 0.6 and 0.8. The numerical results are compared with the existing experimental data in the literature showing a reasonable agreement. The results indicate that decrease in size of the bubble diameter increases mass flow rate of liquid at constant submergence ratios. The present study reports the improved performance of this pump with decrease in bubble size and increase in angle of tapered upriser pipe. Moreover, the results show that the tapered upriser pipe with 3° tapering angle gives the highest efficiency at nearly all submergence ratios. Further, the highest efficiency of the pump is shown to be at the largest submergence ratio, namely 0.8.

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