Qualification of an Afterburner Thrust Augmentation System for an Aero Gas Turbine Engine

Author(s):  
R. K. Mishra

Qualification of afterburner thrust augmentation system in stand-alone mode prior to its flight trials plays a vital role in aero engine application. A full-scale afterburner system was studied to demonstrate its performance parameters such as pressure loss, combustion efficiency, liner temperature at full and part load conditions. Light-off characteristics at different altitude-flight Mach combination were also established. The afterburner system also was activated for considerable time to validate its integrity and performance. The paper presents the various tests carried out on the afterburner and their results. The paper also highlights the jet nozzle matching at various throttle position and studies on combustion instability from qualification point of view. Satisfactory demonstration of performance of the afterburner without encountering screech or buzz over the operating range qualifies the system for its application in the aero engine for limited operation.

2019 ◽  
Vol 36 (3) ◽  
pp. 257-269
Author(s):  
Yinli Xiao ◽  
Zhibo Cao ◽  
Changwu Wang

Abstract In aero-engine combustor, the primary and secondary dilution air jets play a vital role to achieve efficient combustion and provide a satisfactory temperature profile at the combustor exit. In the current research, seven kinds of three-dome combustor sector associated with different dilution holes arrangements are simulated using Flamelet model. The influences of location, number and diameter of dilution air holes on flow field and performance of combustor are analysed in detail. The results demonstrate that the variation of airflow distribution, while keeping the total admission area constant, impact the combustion efficiency and pattern profile considerably, yet has insignificant effect on the total pressure coefficient. The maximum combustion efficiency and minimum pattern factor can be achieved simultaneously with deliberate dilution jet holes arrangement.


2015 ◽  
Vol 119 (1221) ◽  
pp. 1397-1414 ◽  
Author(s):  
N. V. Nguyen ◽  
J.-W. Lee ◽  
M. Tyan ◽  
D. Lee

AbstractThis paper describes a possibility-based multidisciplinary optimisation for electric-powered unmanned aerial vehicles (UAVs) design. An in-house integrated UAV (iUAV) analysis program that uses an electric-powered motor was developed and validated by a Predator A configuration for aerodynamics, weight, and performance parameters. An electric-powered propulsion system was proposed to replace a piston engine and fuel with an electric motor, power controllers, and battery from an eco-system point of view. Moreover, an in-house Possibility-Based Design Optimisation (iPBDO) solver was researched and developed to effectively handle uncertainty variables and parameters and to further shift constraints into a feasible design space. A sensitivity analysis was performed to reduce the dimensions of design variables and the computational load during the iPBDO process. Maximising the electric-powered UAV endurance while solving the iPBDO yields more conservative, but more reliable, optimal UAV configuration results than the traditional deterministic optimisation approach. A high fidelity analysis was used to demonstrate the effectiveness of the process by verifying the accuracy of the optimal electric-powered UAV configuration at two possibility index values and a baseline.


Author(s):  
D. N. Anderson

Three noble-metal monolithic catalysts were tested in a 12-cm-dia combustion test rig to obtain emissions and performance data at conditions simulating the operation of a catalytic combustor for an automotive gas turbine engine. Tests with one of the catalysts at 800 K inlet mixture temperature, 3 × 105 Pa (3 atm) pressure, and a reference velocity (catalyst bed inlet velocity) of 10 m/sec demonstrated greater than 99 percent combustion efficiency for reaction temperatures higher than 1300 K. With a reference velocity of 25 m/sec the reaction temperature required to achieve the same combustion efficiency increased to 1380 K. The exit temperature pattern factors for all three catalysts were below 0.1 when adiabatic reaction temperatures were higher than 1400 K. The highest pressure drop was 4.5 percent at 25 m/sec reference velocity. Nitrogen oxides emissions were less than 0.1 g NO2/kg fuel for all test conditions.


Author(s):  
Gantayata Gouda ◽  
Balaji Sankar ◽  
Venkat Iyengar ◽  
Jana Soumendu

Modifications to the critical parameters, such as the exhaust nozzle area, are sometimes done during maintenance of aircraft engines. These modifications are done either to increase the design thrust or to compensate for the reduction of thrust due to leakage in the variable area jet nozzle. There is a trade-off between several performance parameters when such critical parameters are changed during maintenance. A tuned aerothermodynamic simulation model that agrees well with the experimental data from the original engine is required to study the effect of these changes. In the present work, a multipoint map scaling approach and a parameter estimation method are used to develop a simulation model that agrees well with the experimental data from the original turbojet engine. The design modifications are then incorporated in the model, and the effect of the modification on the various performance parameters is studied. The effect of leakage in the nozzle flaps and the corresponding reduction required in the nozzle throat area are calculated. It is shown that the tuned model developed with experimental testbed data enables the identification of ancillary effects of a change in a design parameter, such as the nozzle throat area.


2004 ◽  
Vol 15 (3) ◽  
pp. 246-246
Author(s):  
M.A. Tony ◽  
A. Butschke ◽  
J. Zagon ◽  
H. Broll ◽  
M. Schauzu ◽  
...  

2021 ◽  
Vol 11 (10) ◽  
pp. 4628
Author(s):  
Macarena Iniesta-Pallarés ◽  
Consolación Álvarez ◽  
Francisco M. Gordillo-Cantón ◽  
Carmen Ramírez-Moncayo ◽  
Pilar Alves-Martínez ◽  
...  

Current agricultural productivity depends on an exogenous nutrient supply to crops. This is of special relevance in cereal production, a fundamental part of the trophic chain that plays a vital role in the human diet. However, our agricultural practices entail highly detrimental side-effects from an environmental point of view. Long-term nitrogen fertilization in croplands results in degradation of soil, water, and air quality, producing eutrophication and subsequently contributing to global warming. In accordance with this, there is a biotechnological interest in using nitrogen-fixing microorganisms to enhance crop growth without adding chemically synthesized nitrogen fertilizers. This is particularly beneficial in paddy fields, where about 60% of the synthetic fertilizer that has been applied is dissolved in the water and washed away. In these agricultural systems, N2-fixing cyanobacteria show a promising biotechnological potential as biofertilizers, improving soil fertility while reducing the environmental impact of the agricultural practice. In the current study, Andalusian paddy fields have been explored to isolate N2-fixing cyanobacteria. These endogenous microorganisms have been subsequently re-introduced in a field trial in order to enhance rice production. Our results provide valuable insights regarding the use of an alternative natural source of nitrogen for rice production.


Polymers ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1175
Author(s):  
Tereza Kroulíková ◽  
Tereza Kůdelová ◽  
Erik Bartuli ◽  
Jan Vančura ◽  
Ilya Astrouski

A novel heat exchanger for automotive applications developed by the Heat Transfer and Fluid Flow Laboratory at the Brno University of Technology, Czech Republic, is compared with a conventional commercially available metal radiator. The heat transfer surface of this heat exchanger is composed of polymeric hollow fibers made from polyamide 612 by DuPont (Zytel LC6159). The cross-section of the polymeric radiator is identical to the aluminum radiator (louvered fins on flat tubes) in a Skoda Octavia and measures 720 × 480 mm. The goal of the study is to compare the functionality and performance parameters of both radiators based on the results of tests in a calibrated air wind tunnel. During testing, both heat exchangers were tested in conventional conditions used for car radiators with different air flow and coolant (50% ethylene glycol) rates. The polymeric hollow fiber heat exchanger demonstrated about 20% higher thermal performance for the same air flow. The efficiency of the polymeric radiator was in the range 80–93% and the efficiency of the aluminum radiator was in the range 64–84%. The polymeric radiator is 30% lighter than its conventional metal competitor. Both tested radiators had very similar pressure loss on the liquid side, but the polymeric radiator featured higher air pressure loss.


Materials ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4284
Author(s):  
Lvtao Zhu ◽  
Mahfuz Bin Rahman ◽  
Zhenxing Wang

Three-dimensional integrated woven spacer sandwich composites have been widely used as industrial textiles for many applications due to their superior physical and mechanical properties. In this research, 3D integrated woven spacer sandwich composites of five different specifications were produced, and the mechanical properties and performance were investigated under different load conditions. XR-CT (X-ray computed tomography) images were employed to visualize the microstructural details and analyze the fracture morphologies of fractured specimens under different load conditions. In addition, the effects of warp and weft direction, face sheet thickness, and core pile height on the mechanical properties and performance of the composite materials were analyzed. This investigation can provide significant guidance to help determine the structure of composite materials and design new products according to the required mechanical properties.


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