Effect of the flow rate of injected air on the temperature of porous wall in the supersonic flow

2021 ◽  
Vol 175 ◽  
pp. 121382
Author(s):  
Alexander Leontiev ◽  
Boris Kichatov ◽  
Alexey Korshunov ◽  
Vladimir Gubernov ◽  
Alexey Kiverin
Keyword(s):  
Supersonic Flow ◽  
Flow Rate ◽  
Porous Wall

To the Problem of Friction Minimization on Permeable Surfaces at Supersonic Flow Rate

2018 ◽  
Vol 61 (3) ◽  
pp. 391-395
Author(s):  
K. G. Garaev ◽  
I. R. Mukhametzyanov
Keyword(s):  
Supersonic Flow ◽  
Flow Rate

Application of Air Microblowing Through a Porous Wall for Skin Friction Reduction on a Flat Plate

2010 ◽  
Vol 5 (3) ◽  
pp. 38-46
Author(s):  
Vladimir I. Kornilov ◽  
Andrey V. Boiko
Keyword(s):  
Boundary Layer ◽  
Flat Plate ◽  
Skin Friction ◽  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Porous Wall ◽  
Friction Reduction ◽  
Local Skin ◽  
Skin Friction Reduction

The effect of air microblowing through a porous wall on the properties of a turbulent boundary layer formed on a flat plate in an incompressible flow is studied experimentally. The Reynolds number based on the momentum thickness of the boundary layer in front of the porous insert is 3 900. The mass flow rate of the blowing air per unit area was varied within Q = 0−0.0488 кg/s/m2 . A consistent decrease in local skin friction, reaching up to 45−47 %, is observed to occur at the maximal blowing air mass flow rate studied.

Effect of gaseous coolant temperature on the transpiration cooling for porous wall in the supersonic flow

2019 ◽  
Vol 142 ◽  
pp. 118433 ◽  
Author(s):  
Alexandr Leontiev ◽  
Andrei Saveliev ◽  
Boris Kichatov ◽  
Alexey Kiverin ◽  
Alexey Korshunov ◽  
...  
Keyword(s):  
Supersonic Flow ◽  
Porous Wall ◽  
Coolant Temperature ◽  
Transpiration Cooling ◽  
Gaseous Coolant

Experimental Investigation of Methane/Air Penetration Combustion and Flame Stability Characteristics on Porous Wall Surface

2013 ◽  
Vol 732-733 ◽  
pp. 190-193 ◽  
Author(s):  
Xiao Feng Zheng ◽  
Yaoxun Feng ◽  
Ming Sheng Jia
Keyword(s):  
Porous Medium ◽  
Flow Rate ◽  
Porous Plate ◽  
Porous Wall ◽  
Flame Stability ◽  
Wall Surface ◽  
Mean Velocity ◽  
Mixture Flow ◽  
Flat Flame ◽  
Air Penetration

Aimed to optimize the design of micro combustor whose chamber based on porous medium wall surface, combustion and flame stability characteristics on porous wall surface with methane/air flat flame were investigated experimentally in this paper. The experimental results show that stable flat flame can be formed on the porous medium surface within given ranges of fuel equivalence ratio and flow rate. When mixture flow rate increasing, the thickness of flame decreases firstly and then increases, and standoff distance of flames decreases quickly and then is unchanged. At higher mean velocity of mixture, the flame moves closer to the porous plate surface, and the minimum distance needing for keeping stable flames decreases. The heat exchange between the porous plate and the mixture can not only preheat mixture but also cool the porous plate.

Experimental and numerical investigations of choked air flow and heat transfer in a ball valve for optimization the cross-sectional area

2019 ◽  
Vol 30 (5) ◽  
pp. 2705-2737 ◽  
Author(s):  
Davood Toghraie ◽  
Hojjatollah Heidari Khouzani
Keyword(s):  
Fluid Flow ◽  
Supersonic Flow ◽  
Flow Control ◽  
Cross Section ◽  
Flow Rate ◽  
Ball Valve ◽  
Flow Coefficient ◽  
Fluid Flow Rate ◽  
Content Type ◽  
Percentage Difference

Purpose The purpose of this study is to understand the functional properties of ball valve in a compressible flow and simulation of experimental data collection of ball valve, was completely simulated. Design/methodology/approach Equations are solved according to finite volume and simplified algorithms. By measuring the flow parameters, including pressure and temperature at different points in the simulation circuit, flow coefficients and localized drop in the valve were determined in different openness cases of test valve and compared with experimental results. Determining a graph for flow coefficient variations in terms of the percentage of openness of the valve is very effective on the flow control as well as on optimizing its cross-section. Findings In the supersonic flow, flow coefficients and local drops of the valve are dependent on several parameters, including fluid flow rate. Flow coefficient graphs at different angles of the test valve show that by increasing the valve opening angle, the flow coefficient increases so that it reaches from 1.72 m3/h at a 30° angle to 46.29 m3/h at a 80° angle. It should be noted that these values in the experimental test were obtained 1.53 m3/h and 49.68 m3/h, respectively, and the percentage difference of these values by simulation was obtained for the angle of 30 degrees 11.7% and for the angle of 80°, about 7% per hour at an angle of 80°. Also, the coefficients of localized loss at different angles of test valve show that by increasing the angle of opening of the valve, the amount of localized loss decreases, so that the average value of 1515.2 in the angle of 30° reaches 1.9 at an angle of 80°. The percentage difference of these values by simulation, for the angle of 30° and 3.5% for the angle of 80°, was about 11.1%. Originality/value Determining a graph for flow coefficient variations versus the percentage of openness of the valve is very effective on the flow control as well as on optimizing its cross-section. In the supersonic flow, flow coefficients and local drop coefficients of the valve are dependent on several parameters, including fluid flow rate.

Using a Bowed Blade to Improve the Supersonic Flow Performance in the Nozzle of a Supersonic Industrial Steam Turbine

2017 ◽  
Vol 139 (10) ◽  
Author(s):  
Hong Yao ◽  
Xun Zhou ◽  
Zhongqi Wang
Keyword(s):  
Shock Wave ◽  
Supersonic Flow ◽  
Steam Turbine ◽  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Wave Structure ◽  
Shock Wave Structure ◽  
Waste Energy ◽  
Low Mass

For solar plants, waste-energy recovery, and turbogenerators, there is a considerable amount of waste energy due to low mass flow rate. Owing to the high specific power output and large pressure ratios across the turbine, a supersonic industrial steam turbine (IST) is able to utilize the waste energy associated with low mass flow rate. Supersonic IST has fewer stages than conventional turbines and a compact and modular design, thus avoiding the excessive size and manufacturing cost of conventional IST. Given their flexible operation and ability to function with loads in the range of 50–120% of the design load, supersonic IST offers significant advantages compared to conventional IST. The strong shock-wave loss caused by supersonic flows can be reduced by decreasing the shock intensity and reducing its influence; consequently, a supersonic IST can reach higher efficiency levels. Considering the demonstrated utility of bowed blades in conventional IST, this paper presents a study of the use of bowed blades in a supersonic IST. For this purpose, first, the shock-wave structure in the supersonic flow field was analyzed and compared with experimental results. Then, four different bowed blades were designed and compared with a straight blade to study the influence of bowed blades on the shock-wave structure and wetness. The results indicate that S-shaped bowing can improve the efficiency of supersonic turbines, and the energy-loss coefficient of the stators can be decreased by 2.4% or more under various operating conditions.

Supersonic Cone with Surface Blowing

1976 ◽  
Vol 27 (4) ◽  
pp. 243-256 ◽  
Author(s):  
E Carafoli ◽  
C Berbente
Keyword(s):  
Supersonic Flow ◽  
Velocity Field ◽  
Equations Of Motion ◽  
Porous Wall ◽  
Circular Cone ◽  
The Body ◽  
Fluid Injection ◽  
Exact Results ◽  
Practical Applications ◽  
Analytical Formulae

SummaryThe velocity field around a circular cone in supersonic flow is determined by considering fluid injection and suction through the porous wall of the body. By using a new method of linearisation of the equations of motion, analytical formulae are obtained which yield almost exact results, as compared with numerical calculations. In addition, the method proposed suggests new problems related to fluid injection and suction which are important for practical applications.

scholarly journals Combustion in a supersonic flow using a pylon equipped with a plasma actuator

2021 ◽  
Vol 2100 (1) ◽  
pp. 012017
Author(s):  
A A Firsov ◽  
N S Kolosov
Keyword(s):  
Supersonic Flow ◽  
Flow Rate ◽  
Energy Input ◽  
Supersonic Flows ◽  
Plasma Actuator ◽  
Combustion Chambers ◽  
Fuel Flow Rate ◽  
Plasma Assisted Combustion ◽  
Fuel Flow ◽  
Wide Range

Abstract Plasma-assisted combustion approach is well known for organizing stable ignition and flame holding in supersonic flows in model scramjet combustion chambers. In this work, a new geometry of pylon equipped by electrodes relative to developed earlier was proposed and experimentally investigated. Stable ignition and flame holding were obtained over a wide range of fuel flow rate and discharge currents. Reducing of the energy input in comparison with the previously considered configurations was also demonstrated.

scholarly journals A Numerical Study on the Characteristics of Air–Fuel Mixing Using a Fluidic Oscillator in Supersonic Flow Fields

Energies ◽  
2019 ◽  
Vol 12 (24) ◽  
pp. 4758 ◽  
Author(s):  
Eun Cheol Lee ◽  
Seung-Won Cha ◽  
Hee-Soo Kwon ◽  
Tae-Seong Roh ◽  
Hyoung Jin Lee
Keyword(s):  
Supersonic Flow ◽  
Flow Field ◽  
Mass Flow Rate ◽  
Flow Rate ◽  
Pressure Loss ◽  
Total Pressure ◽  
Total Pressure Loss ◽  
Fuel Distribution ◽  
Fluidic Oscillator ◽  
Fuel Mixing

In this study, numerical simulations were conducted to confirm the possibility of improved mixing performance by using a fluidic oscillator as a fuel injector. Three-dimensional URANS non-reacting simulations were conducted to examine air–fuel mixing in a supersonic flow field of Mach 3.38. The numerical methods were validated through simulations of the oscillating flow generated from the fluidic oscillator. The results show that the mass flow rate and momentum are reduced at the outlet because the total pressure loss increases inside the fluidic oscillator, which means that higher pressure needs to be applied to supply the same mass flow rate. The simulation showed that the flow structure varies over time as the injected flow is swept laterally. With lateral injection, the fuel distribution is long and narrow, and asymmetric vortexes are generated. However, with central injection, the fuel distribution is relatively similar to the case of using a simple injector. Compared to the simple injector, the penetration length, flammable area, and mixing efficiency were improved. However, the total pressure loss in the flow field increases as well. The results showed that the supersonic fluidic oscillator could be fully utilized as a means to enhance the mixing effect, however a method to reduce the total pressure loss is necessary for practical application.

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