First and Second Law Analysis of Future Aircraft Engines

Abstract

An optimal baseline turbofan cycle designed for a performance level expected to be available around year 2050 is established. Detailed performance data are given in take-off, top of climb and cruise to support the analysis. Losses are analyzed based on a combined use of the first and second law of thermodynamics, to establish a basis for discussion on future radical engine concepts and to quantify loss levels of very high performance engines. In the light of the performance of the future baseline engine, three radical cycles designed to reduce the observed major loss sources are introduced. The combined use of a first and second law analysis of an open rotor engine, an intercooled recuperated engine and an engine working with a pulse detonation combustion core is presented. In the past, virtually no attention has been paid to the systematic quantification of the irreversibility rates of such radical concepts. Previous research on this topic has concentrated on the analysis of the turbojet and the turbofan engine. In the framework developed, the irreversibility rates are quantified through the calculation of the exergy destruction per unit time. A striking strength of the analysis is that it establishes a common currency for comparing losses originating from very different physical sources of irreversibility. This substantially reduces the complexity of analyzing and comparing losses in aero engines. In particular, the analysis sheds new light on how the intercooled recuperated engine establishes its performance benefits.

A Comparison of Steady-State Models for Pressure Gain Combustion in Gas Turbine Performance Simulation

“…Furthermore, these models were investigated in a gas turbine engine from a thermodynamic perspective such as in (Snyder & Nalim, 2012). Studies on the integration into a gas turbine using realistic side conditions have been performed by (Grönstedt, et al, 2014), (Xisto, et al, 2017), (Sousa, et al, 2017) and (Stathopoulos, 2018). Still, complete gas turbine optimisations regarding thermal efficiency for various combustor models and their comparison using realistic constraints are not yet available.…”

Adopting exergy analysis for use in aerospace

“…Noticing the lack of diversity in exergy analysis application beyond turbojet and turbofan, Grönstedt [56] included other potential future engines, using an assumed future 2050 optimised turbofan configuration as the baseline. Grönstedt performed an exergy analysis on an (futuristic) open rotor engine from Chalmers University, an intercooled recuperated engine and an engine working with a pulse detonation combustion core, which are the three alternative configurations he saw as the future of aircraft propulsion (see Fig.…”

“…In particular, the analysis sheds new light on how the intercooled recuperated engine establishes its performance benefits... As part of analyzing the computational results it has become evident that exergy analysis is also quite rewarding when a comparative analysis of different engine architectures is carried out." [56] An area exergy analysis may prove highly beneficial is in providing evidence for the integration of electric engines, an area of research gaining increasing focus for future aircraft. Schmitz [96] initially shows the shortcomings of traditional analysis methods, and then demonstrates how the unified figures of merit provided by exergy are useful in allowing for consistent comparisons between electric and conventional engines.…”

Ultra Low Emission Technology Innovations for Mid-Century Aircraft Turbine Engines

“…A lost work potential, previously described in [10], has been used to evaluate the cruise performance of a fictitious state-ofthe-art turbofan engine. The terms have broadly been distributed onto its components as shown in Figure 2.…”