TURBOJET ENGINE PERFORMANCE CHARACTERISTICS WITH REFERENCE TO METHODS OF AUGMENTATION

1948 ◽  
Author(s):  
Edward Woll
2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Ozgur Balli ◽  
Alper Dalkıran ◽  
Tahir Hikmet Karakoç

Purpose This study aims to investigate the aviation, energetic, exergetic, environmental, sustainability and exergoeconomic performances of a micro turbojet engine used in unmanned aerial vehicles at four different modes. Design/methodology/approach The engine data were collected from engine test cell. The engine performance calculations were performed for four different operation modes. Findings According to the results, maximum energy and exergy efficiency were acquired as 19.19% and 18.079% at Mode 4. Total cost rate was calculated as 6.757 $/h at Mode-1, which varied to 10.131 $/h at Mode-4. Exergy cost of engine power was observed as 0.249 $/MJ at Mode-1, which decreased to 0.088 $/MJ at Mode-4 after a careful exergoeconomic analysis. Originality/value The novelty of this work is the capability to serve as a guide for similar systems with a detailed approach in the thermodynamic, thermoeconomic and environmental assessments by prioritizing efficiency, fuel consumption and cost formation. This investigation intends to establish a design of the opportunities and benefits that the thermodynamic approach provides to turbojet engine systems.


Author(s):  
Jakub Lasocki

The World-wide harmonised Light-duty Test Cycle (WLTC) was developed internationally for the determination of pollutant emission and fuel consumption from combustion engines of light-duty vehicles. It replaced the New European Driving Cycle (NEDC) used in the European Union (EU) for type-approval testing purposes. This paper presents an extensive comparison of the WLTC and NEDC. The main specifications of both driving cycles are provided, and their advantages and limitations are analysed. The WLTC, compared to the NEDC, is more dynamic, covers a broader spectrum of engine working states and is more realistic in simulating typical real-world driving conditions. The expected impact of the WLTC on vehicle engine performance characteristics is discussed. It is further illustrated by a case study on two light-duty vehicles tested in the WLTC and NEDC. Findings from the investigation demonstrated that the driving cycle has a strong impact on the performance characteristics of the vehicle combustion engine. For the vehicles tested, the average engine speed, engine torque and fuel flow rate measured over the WLTC are higher than those measured over the NEDC. The opposite trend is observed in terms of fuel economy (expressed in l/100 km); the first vehicle achieved a 9% reduction, while the second – a 3% increase when switching from NEDC to WLTC. Several factors potentially contributing to this discrepancy have been pointed out. The implementation of the WLTC in the EU will force vehicle manufacturers to optimise engine control strategy according to the operating range of the new driving cycle.


2019 ◽  
Vol 123 (1261) ◽  
pp. 340-355 ◽  
Author(s):  
S. M. Choi ◽  
S. Kim ◽  
R. S. Myong ◽  
W. Kim

ABSTRACTInfrared signal measurements from a micro-turbojet engine are conducted to understand the characteristics of the engine performance and the infrared signal by varying the exhaust nozzle configuration. A cone type nozzle and five rectangle type nozzles whose aspect ratios vary from one to five are used for this experimental work. As a result, it is confirmed that the thrust and the fuel consumption rate of the engine do not change greatly by varying the exhaust nozzle shape. In the case of the aspect ratio of 5, the specific fuel consumption of the engine is increased by about 3% compared to the reference cone nozzle, but the infrared signal can be reduced by up to 14%. As a result of measuring the temperature distribution of the plume gas, the correlation of infrared signal with plume gas temperature distribution can be understood. In the case of a cone shape, the distribution of plume gas formed to circular shape, and the high-temperature core region of plume gas continued to develop farther to the downstream. However, the temperature distribution was maintained in the rectangular shape as the aspect ratio increased, and the average temperature decreased sharply. As the aspect ratio increases, the plume spreads more widely.


2020 ◽  
Vol 142 (8) ◽  
Author(s):  
Mayank Kapoor ◽  
Narendra Kumar ◽  
Ajay Singh Verma ◽  
Gaurav Gautam ◽  
Aditya Kumar Padap

Abstract This paper depicts Box-Behnken design (BBD) approach to optimize the performance and emission characteristics of adjustable compression ratio, single- cylinder diesel engine with nanoparticle-blended biofuel. Cerium oxide (CeO2) nanoparticles and diethyl ether (DEE) are mixed with neem methyl ester (NME) in corresponding ratios as per BBD experimental plan. Engine performance characteristics brake thermal efficiency (BTE), brake-specific fuel consumption (BSFC), and NOx, CO, HC, and CO2 emissions have been analyzed. To study the influence of input parameters, quadratic models are developed on each output response using analysis of variance (ANOVA). Desirability function approach has been used to optimize the performance of multi-response parameters. The results revealed that nanoparticles mixed blends of NME and DEE enhances the performance characteristics and reduce the harmful emissions.


1961 ◽  
Vol 83 (3) ◽  
pp. 303-320 ◽  
Author(s):  
Karl Kovach ◽  
D. M. Sandercock

A five-stage axial-flow compressor with all rotors operating with transonic relative inlet Mach numbers was designed as a research vehicle at the Lewis Research Center in 1952. The compressor was designed and tested as a component of a turbojet engine. This paper summarizes the research work done on this compressor including the aerodynamic design and detailed performance characteristics.


Author(s):  
Takeshi Tagashira ◽  
Takuya Mizuno ◽  
Masaharu Koh ◽  
Nanahisa Sugiyama

This paper introduces a model based control system for a single spool turbojet engine. It consists of a feedback control (FBC) and a component level model (CLM) enhanced by the Constant Gain Extended Kalman Filter (CGEKF). The control system is implemented on a rugged PC, and verified to run in much faster than real time, which is essential requirement for a model based control. Then, the model based control system developed is applied to an actual engine and evaluation test is conducted by using an Altitude Test Facility (ATF). Several types of model based feedback controls are evaluated under various flight conditions, giving intentional engine performance change by varying nozzle area, and intentional sensor failure. It is concluded that the model based control using CGEKF is stable and shows good control performances over the whole flight envelope.


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