Thermodynamic Performance and Creep Life Assessment Comparing Hydrogen- and Jet-Fueled Turbofan Aero Engine

Abstract

There is renewed interest in hydrogen as an alternative fuel for aero engines, due to their perceived environmental and performance benefits compared to jet fuel. This paper presents a cycle, thermal performance, energy and creep life assessment of hydrogen compared with jet fuel, using a turbofan aero engine. The turbofan cycle performance was simulated using a code developed by the authors that allows hydrogen and jet fuel to be selected as fuel input. The exergy assessment uses both conservations of energy and mass and the second law of thermodynamics to understand the impact of the fuels on the exergy destruction, exergy efficiency, waste factor ratio, environmental effect factor and sustainability index for a turbofan aero engine. Finally, the study looks at a top-level creep life assessment on the high-pressure turbine hot section influenced by the fuel heating values. This study shows performance (64% reduced fuel flow rate, better SFC) and more extended blade life (15% increase) benefits using liquefied hydrogen fuel, which corresponds with other literary work on the benefits of LH2 over jet fuel. This paper also highlights some drawbacks of hydrogen fuel based on previous research work, and gives recommendations for future work, aimed at maturing the hydrogen fuel concept in aviation.

Equivalent Analysis of Thermo-Dynamic Blow-Off Impulse under X-ray Irradiation

“…No definite conclusion has been drawn about the distribution of X-ray blow-off impulse with the angle. When Cost [1,4] calculated the impulse of cylindrical shell by X-ray, the X-ray on the surface of cylindrical shell is in fact cosine distribution with the angle of incidence. Thus, it was intuitively assumed that the blow-off impulse is cosine distribution, whereas there is no corresponding proof and applicable conditions.…”

“…A clear conclusion from analytical deduction and derivation is difficult to draw since formula is overly sophisticated about X-ray energy deposition of blackbody spectrum. Cost conducted an analytical deduction of the energy deposition on the surface of cylindrical shells irradiated by X-ray in different directions [4], and the conclusion was also unsatisfactory. He also calculated and analyzed the blow-off impulse of cylindrical shell by X-ray, whereas the numerical results cannot account for the problem since the relation is not the same between the different direction of two-dimensional mesh and the incidence direction of X-ray.…”

“…Since the 1950s and 1960s, the study on multiple effects of X-ray has aroused extensive attention, especially on X-ray thermodynamic effects as a basic mean of spacecraft damage [1-3] has aroused extensive attention. In terms of the mentioned effects, a combination of laboratory and numerical simulations is required [4][5][6]. In the past half century, people have extensively developed a variety of simulation experimental equipment, such as lowenergy relativistic electron beam accelerator [7,8], etc., as well as a series of related software in terms of calculation [9][10][11].…”

Advanced Power Generation Using a Nitrogen Turbine Engine Instead of a Conventional Injection Steam Turbine Engine

“…However, there is a chance in the future that production costs would be lower as the method of battery production is improved [12][13][14][15][16][17][18][19][20][21][22][23]. Technology Description Basic Process is a theory which describes the thermodynamic cycle for the steam turbine which is known as the Rankine cycle [24][25][26]. This cycle is the basis for conventional power generating stations and consists of a heat source (boiler) that converts water to high pressure steam.…”

“…The capacity of steam turbines can range from 50 kW to several hundred MWs for large utility power plants. Steam turbines are widely used for combined heat Technology Description Basic Process is a theory which describes the thermodynamic cycle for the steam turbine which is known as the Rankine cycle [24][25][26]. This cycle is the basis for conventional power generating stations and consists of a heat source (boiler) that converts water to high pressure steam.…”