Flow Rate and Pressure Loss of Multiple-Passage Channel Flows with a Plasma Actuator

2019 ◽  
Vol 2019.25 (0) ◽  
pp. 19D12
Author(s):  
Takahiro SAGAWA ◽  
Daichi KANEHARA ◽  
Masatoshi SANO
Keyword(s):  
Flow Rate ◽  
Pressure Loss ◽  
Plasma Actuator ◽  
Channel Flows ◽  
Multiple Passage

scholarly journals Effect of the Flame Dome Depth and Improvement of the Pressure Loss in the Dump Diffuser

1998 ◽  
Author(s):  
Shinji Honami ◽  
Wataru Tsuboi ◽  
Takaaki Shizawa
Keyword(s):  
Velocity Profile ◽  
Reynolds Stress ◽  
Flow Rate ◽  
Pressure Loss ◽  
Total Pressure ◽  
Flow Behavior ◽  
Sudden Expansion ◽  
Mean Velocity ◽  
The Mean ◽  
Stress Profiles

This paper presents the effect of flame dome depth on the total pressure performance and flow behavior in a sudden expansion region of the combustor diffuser without flow entering the dome head. The mean velocity and turbulent Reynolds stress profiles in the sudden expansion region were measured by a Laser Doppler Velocitmetry (LDV) system. The experiments show that total pressure loss is increased, when flame dome depth is increased. Installation of an inclined combuster wall in the sudden expansion region is suggested from the viewpoint of a control of the reattaching flow. The inclined combustor wall is found to be effective in improvement of the diffuser performance. Better characteristics of the flow rate distribution into the branched channels are obtained in the inclined wall configuration, even if the distorted velocity profile is provided at the diffuser inlet.

Design and Testing of a Can Combustor for a Small Gas Turbine Application

2013 ◽  
Author(s):  
K. V. L. Narayana Rao ◽  
N. Ravi Kumar ◽  
G. Ramesha ◽  
M. Devathathan
Keyword(s):  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Gas Turbines ◽  
Pressure Loss ◽  
High Energy ◽  
Experimental Results ◽  
High Mass ◽  
Test Facility ◽  
Design Requirements

Can type combustors are robust, with ease of design, manufacturing and testing. They are extensively used in industrial gas turbines and aero engines. This paper is mainly based on the work carried out in designing and testing a can type combustion chamber which is operated using JET-A1 fuel. Based on the design requirements, the combustor is designed, fabricated and tested. The experimental results are analysed and compared with the design requirements. The basic dimensions of the combustor, like casing diameter, liner diameter, liner length and liner hole distribution are estimated through a proprietary developed code. An axial flow air swirler with 8 vanes and vane angle of 45 degree is designed to create a re-circulation zone for stabilizing the flame. The Monarch 4.0 GPH fuel nozzle with a cone angle of 80 degree is used. The igniter used is a high energy igniter with ignition energy of 2J and 60 sparks per minute. The combustor is modelled, meshed and analysed using the commercially available ansys-cfx code. The geometry of the combustor is modified iteratively based on the CFD results to meet the design requirements such as pressure loss and pattern factor. The combustor is fabricated using Ni-75 sheet of 1 mm thickness. A small combustor test facility is established. The combustor rig is tested for 50 Hours. The experimental results showed a blow-out phenomenon while the mass flow rate through the combustor is increased beyond a limit. Further through CFD analysis one of the cause for early blow out is identified to be a high mass flow rate through the swirler. The swirler area is partially blocked and many configurations are analysed. The optimum configuration is selected based on the flame position in the primary zone. The change in swirler area is implemented in the test model and further testing is carried out. The experimental results showed that the blow-out limit of the combustor is increased to a good extent. Hence the effect of swirler flow rate on recirculation zone length and flame blow out is also studied and presented. The experimental results showed that the pressure loss and pattern factor are in agreement with the design requirements.

Clocking effect in a centrifugal pump with a vaned diffuser

2020 ◽  
Vol 34 (26) ◽  
pp. 2050286
Author(s):  
Fen Lai ◽  
Xiangyuan Zhu ◽  
Yongqiang Duan ◽  
Guojun Li
Keyword(s):  
Centrifugal Pump ◽  
Flow Rate ◽  
Pressure Loss ◽  
Total Pressure ◽  
Radial Force ◽  
Design Flow ◽  
Total Pressure Loss ◽  
Inlet Section ◽  
Centrifugal Pumps ◽  
Installation Angle

The performance and service life of centrifugal pumps can be influenced by the clocking effect. In this study, 3D numerical calculations based on the k-omega shear stress transport model are conducted to investigate the clocking effect in a centrifugal pump. Time-averaged behavior and transient behavior are analyzed. Results show that the optimum diffuser installation angle in the centrifugal pump is [Formula: see text] due to the minimum total pressure loss and radial force acting on the impeller. Total pressure loss, particularly in the volute, is considerably influenced by the clocking effect. The difference in total pressure loss in the volute at different clocking positions is 2.75 m under the design flow rate. The large total pressure loss in the volute is primarily caused by the large total pressure gradient within the vicinity of the volute tongue. The radial force acting on the impeller is also considerably affected by the clocking effect. When the diffuser installation angle is [Formula: see text], flow rate fluctuations in the volute and impeller passage are minimal, and flow rate distribution in the diffuser passage is more uniform than those in other diffuser installation angles. Moreover, static pressure fluctuations in the impeller midsection and the diffuser inlet section are at the minimum value. These phenomena explain the minimum radial force acting on the impeller. The findings of this study can provide a useful reference for the design of centrifugal pumps.

The Effects Produced by a Butterfly Valve in a Hydraulic Closed Circuit

2015 ◽  
Vol 811 ◽  
pp. 117-121
Author(s):  
Lucian Mândrea ◽  
Corina Cipu ◽  
Corina Băbuţanu ◽  
Gabriela Oprina
Keyword(s):  
Flow Rate ◽  
Pressure Loss ◽  
Volumetric Flow Rate ◽  
Water Velocity ◽  
Flow Coefficient ◽  
Closed Circuit ◽  
Butterfly Valve ◽  
Local Pressure ◽  
Pressure Transducers ◽  
Average Water

The paper presents the operation of a hydraulic closed circuit equipped with a butterfly valve which can close with a step of 10o. Using four pressure transducers and one temperature transducer, the authors determined the volumetric flow rate, the average water velocity and the local pressure loss in the butterfly valve, the flow coefficient Kv and also the incipient cavitation coefficient. Recommendations for the disposal of the butterfly valve are made and conclusions are obtained regarding the range of opening degrees in which the butterfly valve is better to be used.

scholarly journals Numerical Investigation of Mixing Characteristic for CH4/Air in Rotating Detonation Combustor

2020 ◽  
Vol 10 (4) ◽  
pp. 1298
Author(s):  
Shan Jin ◽  
Qingyang Meng ◽  
Zhiming Li ◽  
Ningbo Zhao ◽  
Hongtao Zheng ◽  
...  
Keyword(s):  
Mass Flow ◽  
Flow Rate ◽  
Pressure Loss ◽  
Equivalence Ratio ◽  
Numerical Study ◽  
Ignition Energy ◽  
Flow Rates ◽  
Mass Flow Rates ◽  
Critical Ignition ◽  
Rotating Detonation

The mixing process of fuel and oxidizer is a very critical factor affecting the real operating performance of non-premixed rotating detonation combustor. In this paper, a two-dimensional numerical study is carried out to investigate the flow and mixing characteristics of CH4/air in combustor with different injection structures. On this basis, the effect of CH4/air mixing on the critical ignition energy for forming detonation is theoretically analyzed in detail. The numerical results indicate that injection strategies of CH4 and air can obviously affect the flow filed characteristic, pressure loss, mixing uniformity and local equivalence ratio in combustor, which further affect the critical ignition energy for forming detonation. In the study for three different mass flow rates (the mass flow rates of air are 12.01 kg/s,8.58 kg/s and 1.72 kg/s, respectively), when air is radially injected into combustor (fuel/air are injected perpendicular to each other), although the mixing quality of CH4 and air is improved, the total pressure loss is also increased. In addition, the comparative analysis also shows that the increase of mass flow rate of CH4/air can decrease the difference of the critical ignition energy for forming detonation at a constant total equivalence ratio. The ignition energy decreases with the decrease of the total flow rate and then increases gradually.

scholarly journals Aerodynamic Loss Increase due to Individual Film Cooling Injections From Gas Turbine Nozzle Surface

1998 ◽  
Author(s):  
Ryo Kubo ◽  
Fumio Otomo ◽  
Yoshitaka Fukuyama ◽  
Yuhji Nakata
Keyword(s):  
Gas Turbine ◽  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Pressure Loss ◽  
Rate Ratio ◽  
Flow Rate Ratio ◽  
Design Stage ◽  
Pressure Side ◽  
Mass Flow Rate Ratio

A CFD investigation was conducted on the total pressure loss variation for a linear nozzle guide vane cascade of a gas turbine, due to the individual film injections from the leading edge shower head, the suction surface, the pressure surface and the trailing edge slot. The results were compared with those of low speed wind tunnel experiments. A 2-D Navier-Stokes procedure for a 2-D slot injection, which approximated a row of discrete film holes, was performed to clarify the applicable limitation in the pressure loss prediction during an aerodynamic design stage, instead of a costly 3-D procedure for the row of discrete holes. In mass flow rate ratios of injection to main flow from 0% to 1%, the losses computed by the 2-D procedure agreed well with the experimental losses except for the pressure side injection cases. However, as the mass flow rate ratio was increased to 2.5%, the agreement became insufficient. The same tendency was observed in additional 3-D computations more closely modeling the injection hole shapes. The summations of both experimental and computed loss increases due to individual row injections were compared with both experimental and computed loss increases due to all-row injection with the mass flow rate ratio ranging from 0% to 7%. Each summation agreed well with each all-row injection result. Agreement between experimental and calculated results was acceptable. Therefore, the loss due to all-row injections in the design stage can be obtained by the correlations of 2-D calculated losses from individual row injections. To improve more precisely the summation prediction for the losses due to the present all-row injections, extensive research on the prediction for the losses due to the pressure side injection should be carried out.

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