Experimental Method for Combustion Efficiency Calculation in a Reheat Duct

1988 ◽  
Vol 110 (4) ◽  
pp. 690-694 ◽  
Author(s):  
A. Cadiou
Keyword(s):  
Cross Section ◽  
Static Pressure ◽  
Flow Characteristics ◽  
Combustion Efficiency ◽  
Pressure Measurements ◽  
Two Dimensional ◽  
Combustion Chambers ◽  
Outlet Cross Section ◽  
Gas Sampling ◽  
Flame Holder

An efficient method for the experimental measurement of the combustion efficiency in a reheat duct has been developed at ONERA. Such a method is useful because numerous reheat tests are necessary to study the effect of geometry and flow characteristics on reheat performances. Static pressure measurements along the duct and gas sampling in its outlet cross section are the basis of this downstream-to-upstream method. Experimental results with a tri-annular V-gutter flame holder are presented. These results are also used for comparison with theoretical two-dimensional calculations applied to reheat ducts that ultimately may reduce the number of experiments necessary for the development of reheat combustion chambers.

Computational Analysis of Non-Premixed Combustion in a Scramjet Combustor With a Wedge Shaped Strut Injector

2021 ◽  
Author(s):  
Sajal Katare ◽  
Nagendra P. Yadav
Keyword(s):  
Computational Analysis ◽  
Static Pressure ◽  
Computational Study ◽  
Combustion Process ◽  
Combustion Efficiency ◽  
Reaction Model ◽  
Premixed Combustion ◽  
Cold Flow ◽  
Flame Holder ◽  
Scramjet Combustor

Abstract This paper focuses the computational study of non-premixed combustion in a scramjet combustor. The wedge shaped strut injector was used in the combustion process. In order to investigate the flame holding mechanism of the wedge shaped strut in supersonic flow, the two-dimensional coupled implicit RANS equations, the standard k-ε turbulence model and the finite-rate/eddy-dissipation reaction model are introduced to simulate the flow field of the hydrogen fueled scramjet combustor with a strut flame holder under different conditions. The static pressure of the case under the engine ignition condition is much higher than that of the case under the cold flow condition. The reflection of shock waves improves the mixing of hydrogen with the stream of inlet air and thus increases combustion efficiency. The mass flow rate of air is optimized for the best performance of engine.

scholarly journals FLUID FLOW STUDY IN VARIOUS SHAPES AND SIZES OF HORIZONTAL AXIS SEA CURRENT TURBINE

SINERGI ◽  
2021 ◽  
Vol 25 (3) ◽  
pp. 289
Author(s):  
Wulfilla Maxmilian Rumaherang ◽  
Jonny Latuny
Keyword(s):  
Flow Velocity ◽  
Cross Section ◽  
Cross Sections ◽  
Discharge Coefficient ◽  
Flow Characteristics ◽  
Internal Flow ◽  
Flow Speed ◽  
Diameter Ratio ◽  
Power Coefficient ◽  
Outlet Cross Section

The ducted tidal turbine models have been developed to utilize the conversion of the kinetic energy on ocean currents. The research in refining the turbine characteristics has been carried out by modifying the turbine’s shape and size. This study investigated flow characteristics in the meridional section of five ducted turbines models for seawater flow with velocity U0 = 1.5 m/s. The ducted turbine design and construction have five different impeller house diameters and fixed inlet and outlet diameters. The potential energy flow theory and experimental data are used to analyze the flow characteristics of the model. The results show that flow velocity in the x-direction at the inlet and outlet cross-section is getting smaller, reducing the impeller house cross section. Each impeller house size reduction increases the flow speed in the impeller house cross-section and also pressure on all other cross-sections tested. In the inlet area, the increased pressure indicates a decrease in speed flow and discharge coefficient value. The discharge coefficient value decreases from CQ = 0.9 at the diameter ratio of dr = 1 to CQ = 0.56 at the diameter ratio of dr = 0.375. The maximum value of power coefficient was determined at dr = 0,61÷0.73 or dr = 0.69 which is equivalent to average internal flow velocity Vr =2.0÷2.6 m/s and the static pressure ps = 97.1÷ 94.4 kPa. At the ratio value of D0/D2 = 0.83, the optimal diameter ratio dropt=0,61÷0.73 is in line with the duct model of case 3 and case 4, but it may be determined solely as for case 4.

Flow Analysis for Optimal Configuration of Hemoperfusion Device

1987 ◽  
Vol 10 (2) ◽  
pp. 115-120
Author(s):  
V. Chang ◽  
A. Battistin ◽  
R. Rodrigue ◽  
T.M.S. Chang
Keyword(s):  
Cross Section ◽  
Activated Charcoal ◽  
Flow Analysis ◽  
Flow Characteristics ◽  
Vertical Cross Section ◽  
Two Dimensional ◽  
Cylindrical Container ◽  
Flow Configuration ◽  
Normal Configuration ◽  
Inlet Tube

The objective of this experiment was to determine the flow characteristics of a hemoperfusion device. The standard device consists of a cylindrical container which is tapered towards the outlet end. Flow enters the column through a small inlet tube into the wide frontal area of the column. Having passed through the column containing collodian coated activated charcoal spheres, it leaves by the tapered outlet. In order to achieve our aim, we designed and built a two-dimensional plexiglass model consisting of a vertical cross section of the actual hemoperfusion device. Glass beads were used to simulate the artifi-cal carbon cells and a colored solution was used to enable us to visualize the flow. In the normal configuration, it was determined that stagnation and channelling were present. The model was then analysed in the inverse configuration. This way, flow inlet is through the tapered end and flow outlet is towards the wider cylindrical end. This inverse flow configuration improved the flow characteristics and eliminated most of the channelling and stagnation.

Measurement of Two-Dimensional Periodic Flow With a Cobra Probe

1973 ◽  
Vol 95 (2) ◽  
pp. 295-299 ◽  
Author(s):  
Y. Senoo ◽  
Y. Kita ◽  
K. Ookuma
Keyword(s):  
Pressure Transducer ◽  
Static Pressure ◽  
Flow Characteristics ◽  
Periodic Flow ◽  
Two Dimensional ◽  
Unsteady State ◽  
Pump Impeller ◽  
Pressure Transducers ◽  
Probe System ◽  
Similarity Law

Three semiconductor pressure transducers were inserted into a cobra probe to measure instantaneous condition of flow at the exit of a pump impeller. As it was difficult to calibrate a probe in a two-dimensional periodic flow which was similar to the periodic flow to be measured, the authors used the probe assuming that the steady flow characteristics were valid and examined the results in several ways. The results at different pump speeds satisfied the similarity law of flow from the impeller, and it was concluded that the time response of the probe and pressure transducer system was satisfactory. Almost identical results were obtained regardless of the orientation of the probe, and it was concluded that the calibration curve at steady state was applicable to the unsteady state. Finally, the static pressure calculated from the probe output agreed with the wall pressure which was directly measured with a semiconductor pressure transducer. The authors believe that the three steps are sufficient to prove that the results obtained with the probe are reliable and the probe system is suitable for measurement of periodic flow at the exit of impeller of a pump.

Wall Pressure Measurements in a Convergent–Divergent Nozzle with Varying Inlet Asymmetry

2016 ◽  
Vol 33 (2) ◽  
Author(s):  
C. Senthilkumar ◽  
S. Elangovan ◽  
E. Rathakrishnan
Keyword(s):  
Mach Number ◽  
Supersonic Flow ◽  
Flow Separation ◽  
Static Pressure ◽  
Flow Characteristics ◽  
Pressure Measurements ◽  
Separation Region ◽  
Number Ratio ◽  
Inlet Angle ◽  
Nozzle Inlet

AbstractIn this paper, flow separation of a convergent–divergent (C-D) nozzle is placed downstream of a supersonic flow delivered from Mach 2.0 nozzle is investigated. Static pressure measurements are conducted using pressure taps. The flow characteristics of straight and slanted entry C-D nozzle are investigated for various NPR of Mach 2.0 nozzle. The effect of asymmetry at inlet by providing 15°, 30°, 45° and 57° cut is analyzed. Particular attention is given to the location of the shock within the divergent section of the test nozzle. This location is examined as a function both NPR of Mach 2.0 nozzle and test nozzle inlet angle. Some of the measurements are favorably compared to previously developed theory. A Mach number ratio of 0.81 across the flow separation region was obtained.

Aerodynamic Throttling of a Two-Dimensional Flow by a Thick Jet

1976 ◽  
Vol 27 (3) ◽  
pp. 229-242 ◽  
Author(s):  
J B Stek ◽  
H Brandt
Keyword(s):  
Cross Section ◽  
Rectangular Cross Section ◽  
Maximum Height ◽  
Pressure Measurements ◽  
Two Dimensional ◽  
Pressure Distributions ◽  
Air Jet ◽  
Two Dimensional Flow ◽  
Made In

SummaryThe velocity and pressure distributions in a flow generated by a thick air jet that throttles a confined airstream have been studied analytically and experimentally. Velocity and pressure measurements were made in a duct with a rectangular cross section of 102 mm height and 19 mm depth, through which air flowed at velocities ranging from 65 to 80 m/s. The airstream was throttled by a thick air jet having velocities ranging from 130 to 150 m/s that entered the mainstream at angles ranging from 60° to 135°. The jet-mainstream contour was found to be elliptical and agreement within six per cent was obtained between the theoretically and experimentally determined maximum height of the contour. Jet spreading was found to be linear. The theory permits determination of the velocity profile in the jet and gives velocities that deviate less than ten per cent from values obtained experimentally.

Two-Dimensional Flow Through a Diffuser With an Exit Length

1953 ◽  
Vol 20 (3) ◽  
pp. 390-392
Author(s):  
K. R. Galle ◽  
R. C. Binder
Keyword(s):  
Cross Section ◽  
Static Pressure ◽  
Pressure Rise ◽  
Layer Growth ◽  
Two Dimensional ◽  
Dimensional Flow ◽  
Two Dimensional Flow ◽  
Uniform Cross Section ◽  
Flow Through ◽  
Boundary Layer Growth

Abstract A diffuser with an “exit length” is one with a channel of uniform cross section following the diffuser. Tests were made of different diffusers with and without exit lengths. The data were for steady, incompressible, two-dimensional flow. The performance of each diffuser was improved by the presence of an exit length. As compared to flow without an exit length, flow with an exit length is characterized by a reduced boundary-layer growth, by a small decrease in the pressure rise across the diverging section, and by a decrease in the static-pressure gradient at the diffuser inlet.

The Flow Around Surface-Mounted, Prismatic Obstacles Placed in a Fully Developed Channel Flow (Data Bank Contribution)

1993 ◽  
Vol 115 (1) ◽  
pp. 85-92 ◽  
Author(s):  
R. Martinuzzi ◽  
C. Tropea
Keyword(s):  
Channel Flow ◽  
Static Pressure ◽  
Laser Sheet ◽  
Three Dimensional ◽  
Data Bank ◽  
Pressure Measurements ◽  
Two Dimensional ◽  
Middle Region ◽  
Visualization Techniques ◽  
Separating Flows

The flow field around surface-mounted, prismatic obstacles with different spanwise dimensions was investigated using the crystal violet, oil-film and laser-sheet visualization techniques as well as by static pressure measurements. The aim of this study is to highlight the fundamental differences between nominally two-dimensional and fully three-dimensional obstacle flows. All experiments were performed in a fully developed channel flow. The Reynolds number, based on the height of the channel, lay between 8 × 104 and 1.2 × 105. Results show that the middle region of the wake is nominally two-dimensional for width-to-height ratios (W/H) greater than 6. The separated region in front of wider obstacles is characterized by the appearance of a quasi-regular distribution of saddle and nodal points on the forward face of the obstacles. These three-dimensional effects are considered to be inherent to such separating flows with stagnation.

Computational Analysis of Hydrogen-Fueled Scramjet Combustor Using Cavities in Tandem Flame Holder

2015 ◽  
Vol 772 ◽  
pp. 130-135 ◽  
Author(s):  
Sukanta Roga ◽  
Krishna Murari Pandey
Keyword(s):  
Mach Number ◽  
Computational Analysis ◽  
Static Pressure ◽  
Combustion Efficiency ◽  
Recirculation Region ◽  
Stagnation Temperature ◽  
Computational Results ◽  
Species Transport ◽  
Flame Holder ◽  
Scramjet Combustor

This work presents the computational analysis of scramjet combustor using cavities in tandem flame holder by means of 3D. The fuel used by scramjet combustor with cavities in tandem flame holder is hydrogen, the fluid flow and the work is based on the species transport combustion with standard k-ε viscous model. The Mach number at inlet is 2.47 and stagnation temperature and static pressure for vitiated air are 1000K and 100kPa respectively. These computational analysis is mainly aimed to study the flow structure and combustion efficiency. The computational results are compared qualitatively and quantitatively with experimental results and these are agreed as well. Due to the combustion, the recirculation region behind the cavity injector becomes larger as compared to mixing case which acts as a flame holder. From the analysis, the maximum Mach number of 2.33 is observed in the recirculation areas.

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