scholarly journals Numerical and Experimental Investigations on Performance Optimization of a Microturbojet Engine Combustor

2021 ◽  
Vol 2021 ◽  
pp. 1-6
Author(s):  
Wu He ◽  
Zhihui Guo ◽  
Siyuan Xu ◽  
Yi Jin
Keyword(s):  
Flow Pattern ◽  
Residence Time ◽  
Performance Optimization ◽  
Vortex Flow ◽  
Experimental Investigations ◽  
Flame Stability ◽  
Excess Air ◽  
Airflow Distribution ◽  
Primary Zone ◽  
Design Speed

Sudden extinction of a microturbojet engine combustor was encountered during the engine accelerating process, which motivates the present work to optimize the combustor performance. Numerical results show that by decreasing the primary zone air-introducing area and increasing the dilution zone air-introducing area, the primary zone air percentage is reduced from 39.35% to 32%, and the primary zone excess air ratio is reduced from 1.122 to 0.915, which is believed to be beneficial for flame stability both in terms of residence time and rich burn. Meanwhile, the vortex flow pattern in the primary zone varies little as the variations of the airflow distribution. The new engine, which is equipped with the optimized combustor, is tested by experiments. The successful accelerating to the rotating design speed demonstrates the effectiveness of combustor optimization work.

scholarly journals Application of Deswirl Device in Cyclone Dust Separator

2017 ◽  
Vol 20 (3&4) ◽  
pp. 203-216 ◽  
Author(s):  
M. Z. Abdullah ◽  
Z. Husain ◽  
S. M. Fraser
Keyword(s):  
Vortex Flow ◽  
Flow Instability ◽  
Laser Doppler Anemometry ◽  
Experimental Investigations ◽  
Reduced Pressure ◽  
Constant Flow Rate ◽  
Visualization Experiment ◽  
Vortex Finder ◽  
Dust Separator ◽  
Main Components

The experimental investigations of the vortex flow inside the vortex finder (outlet duct) of the cyclone dust separator have been carried out.  Preliminary study from the visualization experiment has been performed and discovered vortex instability inside the conventional vortex finder.  In order to minimize the instabilities, the streamlined entry shape was inserted at the vortex finder entrance and the results showed remarkable improvement of the vortex flow instability inside the vortex finder.  The velocity measurements of two main components of velocity were performed using a laser-Doppler anemometry at the cyclone vortex finder outlet.  The experiments were conducted at a constant flow rate of 0.0246m3/s with the vortex finder diameter of 64mm and with several types of entrance configuration in order to improve the cyclone performance and to reduce the losses.  The use of deswirl devices inside the vortex finder significantly reduced pressure drop and energy losses.

Vortex Flow Controllers in Sanitary Engineering

1984 ◽  
Vol 106 (2) ◽  
pp. 129-133 ◽  
Author(s):  
H. Brombach
Keyword(s):  
Flow Control ◽  
Flow Pattern ◽  
Flow Resistance ◽  
Vortex Flow ◽  
Vortex Chamber ◽  
Control Problems ◽  
Inlet Port ◽  
Input Pressure ◽  
Conical Vortex ◽  
Moving Parts

Flow control problems in combined sewerage systems can be solved with the aid of a new variation of the vortex amplifier. This valve has no moving parts, and comes under the category of pure fluidics; it has a conical vortex chamber and a single inlet port. Depending on the level of water in the vortex chamber the flow pattern may be either axially symmetrical or axially asymmetrical. This effect enables the device to alter its flow resistance in response to the input pressure. Several hundred of this type of the flow controller are already in operation. An example of their application is described below.

Investigation on Flowfield and Fuel/Air Premixing Uniformities of Low Swirl Injector for Lean Premixed Gas Turbines

2021 ◽  
Author(s):  
Fujun Sun ◽  
Jianqin Suo ◽  
Zhenxia Liu
Keyword(s):  
Penetration Depth ◽  
Residence Time ◽  
Gas Turbines ◽  
Structural Parameters ◽  
Combustible Mixture ◽  
Operating Conditions ◽  
Flame Stability ◽  
Nox Emissions ◽  
Auto Ignition ◽  
Lean Premixed

Abstract Based on the development trend of incorporating fuel holes into swirler-vanes and the advantages of wide operating conditions as well as low NOx emissions of LSI, this paper proposes an original lean premixed LSI with a convergent outlet. The influence of key structures on flowfields and fuel/air premixing uniformities of LSI is investigated by the combination of laser diagnostic experiments and numerical simulations. The flowfields of LSI shows that the main recirculation zone is detached from the convergent outlet and its axial dimensions are smaller than that of HSI, which can decrease the residence time of high-temperature gas to reduce NOx emissions. The fuel/air premixing characteristics show that the positions and diameters of fuel holes affect fuel/air premixing by changing the penetration depth of fuel. And when the penetration depth is moderate, it can give full play to the role of swirling air in enhancing premixing of fuel and air. In addition, the increase of the length of the premixing section can improve the uniformity of fuel/ar premixing, but it can also weaken the swirl intensity and increase the residence time of the combustible mixture within the LSI, which can affect flame stability and increase the risk of auto-ignition. Therefore, the design and selection of LSI structural parameters should comprehensively consider the requirements of fuel/air mixing uniformity, flame stability and avoiding the risk of auto-ignition. The results can provide the technical basis for LSI design and application in aero-derivative and land-based gas turbine combustors.

Optimization of four models flatbread bakery machines in Iran

2019 ◽  
Vol 30 (6) ◽  
pp. 3399-3434 ◽  
Author(s):  
Soroush Sadripour ◽  
Mohammad Estajloo ◽  
Seyed Abdolmehdi Hashemi ◽  
Ali J. Chamkha ◽  
Mahmoud Abbaszadeh
Keyword(s):  
Energy Consumption ◽  
Exergy Efficiency ◽  
Experimental Investigations ◽  
Content Type ◽  
Numerical Studies ◽  
Excess Air ◽  
High Preference ◽  
Energy And Exergy ◽  
Traditional Bread ◽  
Wasted Energy

Purpose The purpose of this study is to reduce energy consumption in bakeries. Due to fulfill this demand, quite a few parameters such as energy and exergy efficiency, energy waste and fuel consumption by different traditional flatbreads bakeries (Sangak, Barbari, Taftun and Lavash should be monitored and their roles should not be neglected. Design/methodology/approach In the present study, experimental measurements and mathematical modeling are used to scrutinize and investigate the effects of the aforementioned parameters on energy consumption by bakeries. Findings The results show that by doing reported methods in this paper, the wasted energy of the walls can be decreased by about 65 per cent; and also, by controlling the combustion reaction to perform with 5 per cent excess air, the wasted energy of excess air declines by about 90 per cent. And finally, the energy and exergy efficiency of bakeries is increased, and as a result, the annual energy consumption of Sangak, Barbari, Taftun and Lavash bakeries diminish about 71, 59, 57 and 40 per cent, respectively. Originality/value As evidenced by the literature review, it can be observed that neither numerical studies nor experimental investigations have been conducted about energy and exergy analyses of Iranian machinery traditional flatbread bakeries. It is clear that due to a high preference of Iranians to use the traditional bread and also the popularity of baking this kind of bread in Iran, if it is possible to enhance the traditional oven conditions to decrease the loss of natural gas instead of industrializing the bread baking, the energy consumption in the country can be optimized.

Aerodynamic and Performance Studies of a Three-Stage High Pressure Research Turbine With 3-D - Blades, Design Point and Off-Design Experimental Investigations

2000 ◽  
Author(s):  
M. T. Schobeiri ◽  
J. L. Gilarranz ◽  
E. S. Johansen
Keyword(s):  
High Pressure ◽  
Performance Studies ◽  
Experimental Investigations ◽  
Performance Measurements ◽  
Multi Stage ◽  
Speed Range ◽  
Design Speed ◽  
And Performance ◽  
Operating Points ◽  
Performance Behavior

This paper deals with the aerodynamic and performance behavior of a three-stage high pressure research turbine with 3-D curved blades at its design and off-design operating points. The research turbine configuration incorporates six rows beginning with a stator row. Interstage aerodynamic measurements were performed at three stations, namely downstream of the first rotor row, the second stator row, and the second rotor row. Interstage radial and circumferential traversing presented a detailed flow picture of the middle stage. Performance measurements were carried out within a rotational speed range of 75% to 116% of the design speed. The experimental investigations have been carried out on the recently established multi-stage turbine research facility at the Turbomachinery Performance and Flow Research Laboratory, TPFL, of the Texas A&M University.

Investigation of Vortex Reacting Flows in Asymmetric Meso Scale Combustor

2013 ◽  
Vol 388 ◽  
pp. 246-250 ◽  
Author(s):  
Mostafa Khaleghi ◽  
Mazlan A. Wahid ◽  
Mohsin M. Seis ◽  
Aminuddin Saat
Keyword(s):  
Flame Structure ◽  
Three Dimensional ◽  
Reacting Flows ◽  
Experimental Investigations ◽  
Flame Stability ◽  
Three Dimensional Flow ◽  
Asymmetric Vortex ◽  
Wide Range ◽  
Basic Characteristics ◽  
Exceptional Stability

In the current study computational and experimental investigations of a turbulent asymmetric vortex flame is presented. The three dimensional flow fields have been described using a computational methodology that impalements the kε turbulence model. The computational model is validated for isothermal flow. Moreover, the visible flame structure was captured by direct photography at a wide range of equivalence ratios in order to emphasize the exceptional stability of such flame. The mechanism of flame stability and interaction with the forced vortex field is preliminarily discussed. Finally, the basic characteristics of the asymmetric vortex flames are concluded.

Laboratory Combustibility Testing of Solid Fuel

1980 ◽  
Vol 102 (3) ◽  
pp. 666-671
Author(s):  
E. C. Winegartner ◽  
C. J. Lin
Keyword(s):  
Residence Time ◽  
Wall Temperature ◽  
Solid Fuels ◽  
Excess Oxygen ◽  
Flame Stability ◽  
Firing Rates ◽  
Low Load ◽  
Carbon Burnout ◽  
Load Conditions

A laboratory furnace having a controlled wall temperature is used to measure the combustibility of coal and other solid fuels. Operation at wall temperatures of 1260–1370°C (2300°–2500° F) permits determination of percent carbon burnout as a function of residence time and excess oxygen under furnace conditions representative of those encountered in large boilers. Operation at decreasing wall temperatures provides information on flame stability under conditions approaching those encountered under low load conditions in operating boilers. Firing rates are generally in the range of 11.7–29.3 KWt (40–100k BTU/hr) permitting testing of 100–150 kg (200–300 lb.) samples which can reasonably be obtained by core drilling or from small pilot units.

Numerical Simulation as Design Optimization Tool for Gas Turbine Combustion Chambers

2010 ◽  
Author(s):  
Digvijay B. Kulshreshtha ◽  
S. A. Channiwala ◽  
Saurabh B. Dikshit
Keyword(s):  
Numerical Simulation ◽  
Temperature Distribution ◽  
Combustion Chamber ◽  
Design Optimization ◽  
Gas Turbine ◽  
Flow Patterns ◽  
Intermediate Zone ◽  
Experimental Investigations ◽  
Combustion Chambers ◽  
Primary Zone

In present study an attempt has been made through CFD approach using CFX 11 to analyze the flow patterns within the combustion liner and through different air admission holes, namely, primary zone, intermediate zone, dilution zone and wall cooling, and from these the temperature distribution in the liner and at walls as well as the temperature quality at the exit of the combustion chamber are predicted. The design optimization is carried out using the CFD results with validation using experimental investigations.

scholarly journals Experimental study and mathematical modeling of the residence time distribution in magnetic mixer

2013 ◽  
Vol 15 (2) ◽  
pp. 53-60 ◽  
Author(s):  
Rafał Rakoczy ◽  
Marian Kordas ◽  
Przemysław Grądzik ◽  
Maciej Konopacki ◽  
Grzegorz Story
Keyword(s):  
Magnetic Field ◽  
Residence Time ◽  
Time Distribution ◽  
Residence Time Distribution ◽  
Rotating Magnetic Field ◽  
Experimental Investigations ◽  
Stirred Tank Reactors ◽  
Continuous Stirred Tank ◽  
Set Up ◽  
Magnetic Mixer

This study reports on research results in the field of a mixing process under the action of a transverse rotating magnetic field (TRMF). The main objective of this paper is to present the effect of this type of a magnetic field on residence time distribution (RTD) measurements. This paper evaluates the performance of a magnetic mixer by comparing the results of an experimental investigations in a pilot set-up and theoretical values obtained from mathematical model. This model consisting of the set of ideal continuous stirred tank reactors (CSTR) fitted well the experimental data.

Investigation of Swirler/Dilution Jet Flow Split on Primary Zone Flow Patterns in a Water Model Can-Type Combustor

1989 ◽  
Vol 111 (2) ◽  
pp. 310-317 ◽  
Author(s):  
P. Koutmos ◽  
J. J. McGuirk
Keyword(s):  
Flow Pattern ◽  
Swirling Flow ◽  
Quantitative Information ◽  
Water Model ◽  
Strong Mixing ◽  
Turbulence Energy ◽  
Mean Velocity ◽  
Primary Zone ◽  
Primary Jets ◽  
Undesirable Feature

LDA measurements of the three mean velocity components and the corresponding turbulence intensities have been made to provide qualitative and quantitative information on the flow field in a water model of a can-type gas turbine combustion chamber. The combustor geometry comprised a swirl-driven primary zone, annulus-fed rows of primary and secondary jets, and an exit contraction. The effect of variation of the flow split between the swirler and the dilution holes on the flow pattern in the primary zone has been investigated in detail. Flow visualization studies revealed that significant changes occur in this region due to the interaction between the swirling flow and the radially directed primary jets. A large toroidal recirculation was formed and high levels of turbulence energy were generated in the core of the combustor at low levels of swirler flow rate. As the swirl level increases, the strength of this recirculation was observed to weaken. Beyond a critical level, the primary recirculation was pushed off center and the undesirable feature of a forward velocity on the combustor axis in the primary zone was observed. Despite the dramatic changes brought about in the primary zone, the flow pattern downstream of the secondary jets was practically the same for all flow splits due to the strong mixing caused by the two rows of jets.

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