Thermophysical Properties Research Literature Retrieval Guide Edited by Y. S. Touloukian, J. K. Gerritsen and N. Y. Moore Second edition, revised and expanded. Book 1: Pp. xxi + 819. Book 2: Pp.621. Book 3: Pp. ix + 1315. (New York: Plenum Press, 1967.) n.p.

/pdf/heat-and-mass-transfer-1yaijfx8vp.pdf

Heat and Mass Transfer

Camelina uses, genetics, genomics, production, and management

Renewable bio-jet fuel production for aviation: A review

With the growing air transport demand and concerns about its environmental impacts, alternative jet fuels derived from non-conventional sources have become an important strategy for achieving a sustainable and green aviation. In the past 10 years, governments around the world along with aviation industry have invested significant efforts into exploring all sorts of alternative jet fuels that can be used to power aircraft engines. Among all the alternative jet fuels explored, the aviation sector has agreed that hydrocarbon-based ‘drop-in’ replacement fuels, which are fully interchangeable and compatible with current conventional jet fuels, would be the best choice in the near future, as they can be used without any modifications to today׳s aircraft or fuel infrastructure. This paper reviews the current state of development of ‘drop-in’ alternative jet fuels including various Fisher–Tropsch synthetic jet fuels and bio-jet fuels. Recent advances in research activities on alternative jet fuels, including fuel property evaluations, combustor component tests, engine tests, and flight tests, are highlighted. Furthermore, basic research needs for understanding the combustion characteristics of alternative jet fuels are underlined and discussed by reviewing recent fundamental combustion studies on ignition, extinction, flame propagation, emissions, and species evolution of various conventional and alternative jet fuels. Recognizing that the use of ‘simpler’ surrogate fuels to emulate the behavior of ‘complex’ alternative jet fuels is of fundamental and practical importance for the development of physics-based models to enable quantitative emissions and performance predictions using combustion modeling, recent studies on surrogate formulation for alternative jet fuels are also reviewed and discussed. This review concludes with a brief discussion of future research directions.

/pdf/recent-development-in-studies-of-alternative-jet-fuel-t7ts9wulr2.pdf

Recent development in studies of alternative jet fuel combustion: Progress, challenges, and opportunities

Sustainability is a concept that integrates at least three dimensions: environmental, economic and social. Energy systems are usually evaluated as a key contributor for sustainable development, needing the methodology used for their evaluation to address many indicators, some are quantitative, while others are qualitative. It is therefore a challenge to choose the best methodology to accomplish this task. In this article, a comprehensive literature review has been performed to analyse which tools have been used by the scientific community for the sustainability evaluation of renewable energy systems during the past ten years (2007–2017). The purpose of this work focuses on verifying that the methodological framework integrated by the Life Cycle Analysis (LCA) and Multi-Criteria Decision Making (MCDM) combination is the right tool for the sustainability evaluation of renewable energy systems and obtaining a set of sustainable indicators, evaluation methods and the context where they are applied (such energy policies, electrical supply and evaluation of projects). A knowledge database has been built from the scientific experience of 154 cases of sustainability evaluation in renewable energy systems, with special focus on photovoltaic systems. The results of this revision show that LCA and MCDM applied individually do not achieve a comprehensive sustainability evaluation, due to their intrinsic high degree of uncertainty and the different kinds of analysed parameters. The hybrid framework of LCA and MCDM applied in combination appears as the most appropriate approach for this purpose, and specifically the combination of LCA and Analytic Herarchic Process (AHP), the most frequently used by the scientific community, for its simplicity and robustness for sustainable evaluation in energy systems.

Life Cycle Analysis with Multi-Criteria Decision Making: A review of approaches for the sustainability evaluation of renewable energy technologies

This paper investigates the impact of thermal management methods on the design point and synthesis exchange rates of an ultra-high bypass ratio geared turbofan engine. In a typical thermal management system, where heat is managed by means of heat exchangers that transfer engine waste heat into oil, air, or fuel. However, the utilization of air–oil and fuel–oil heat exchangers has an adverse impact on engine performance. This paper investigates the impact on and engine’s specific fuel consumption and summarizes it into common exchange rates for different thermal management configurations. The results show that any pressure loss in the bypass duct results in a severe specific fuel consumption penalty (an increase of 1% pressure loss in the bypass duct causes a 2% specific fuel consumption increase at cruise conditions). In addition, quite severe is the impact of extracting air from the gas path, particularly when the bleed location is in the bypass duct or the high-pressure compressor. It is also found that the utilization of a fuel–oil heat exchanger improves the specific fuel consumption at a higher rate than an air–oil heat exchanger. For the performance characteristics of the examined engine, the specific fuel consumption benefit with the former is 1.33%, while for the latter it is 0.38%.

https://www.mdpi.com/2076-3417/10/21/7945/pdf

Exchange rate analysis for ultra high bypass ratio geared turbofan engines

At the preliminary design stage for an aero-engine, the evaluation of the nozzle performance is an important aspect as it affects the overall engine cycle behaviour. Currently, there is a lack of s...

/pdf/computational-fluid-dynamics-based-approach-for-low-order-4ubsb861id.pdf

Computational fluid dynamics-based approach for low-order models of propelling nozzle performance:

Military aircrafts are often subjected to severe flight maneuvers with high Angles-of -Attack (AOA) and Angles of Sideslip (AOSS). These flight attitudes induce non-uniform in flow conditions to their gas turbine engines which may include distortion of inlet total pressure and total temperature at the Aerodynamic Interface Plane (AIP). Operation of the downstream compression system with distorted inflow typically results in reduced aerodynamic performance, reduced stall margin, and increased blade stress levels. In the present study the steady state total pressure distortion induced to the Aerodynamic Interface Plane due to the aircraft’s flight attitude have been estimated in terms of distortion descriptors. The distorted conditions at the interface between the intake and the engine have been predicted by using Computational Fluid Dynamics (CFD), where 33 different aircraft flight attitudes have been tested. Based on the obtained results the effect of Angle-of-Attack (AOA) and Angle of Side Slip (AOSS) on the distortion descriptors have been studied. The results showed that the distortion effect becomes more pronounced whenever this specific airframe configuration is exposed to incoming flow with an AOSS. Among the tested cases, the greatest total pressure defect at the AIP in terms of difference from the average value and of circumferential extent was calculated for the flight attitudes of 0·35M flight with 0° AOA and 8° AOSS and 0·35M fight with 16° AOA and 16° AOSS.

Total pressure distortion levels at the aerodynamic interface plane of a military aircraft

Reduced-dimensional MPC controller for direct thrust control

The next generation of aerial robots will be utilized extensively in real-world applications for different purposes: Delivery, entertainment, inspection, health and safety, photography, search and rescue operations, fire detection, and use in hazardous and unreachable environments. Thus, dynamic modeling and control of drones will play a vital role in the growth phase of this cutting-edge technology. This paper presents a systematic approach for control mode identification of JetQuads (gas turbine-powered quads) that should be satisfied simultaneously to achieve a safe and optimal operation of the JetQuad. Using bond graphs as a powerful mechatronic tool, a modular model of a JetQuad including the gas turbine, electric starter, and the main body was developed and validated against publicly available data. Two practical scenarios for thrust variation as a function of time were defined to investigate the compatibility and robustness of the JetQuad. The simulation results of these scenarios confirmed the necessity of designing a compatibility control loop, a stability control loop, and physical limitation control loops for the safe and errorless operation of the system. A control structure with its associated control algorithm is also proposed to deal with future challenges in JetQuad control problems.

Theoklis Nikolaidis

Papers

Exchange rate analysis for ultra high bypass ratio geared turbofan engines

Computational fluid dynamics-based approach for low-order models of propelling nozzle performance:

Total pressure distortion levels at the aerodynamic interface plane of a military aircraft

Reduced-dimensional MPC controller for direct thrust control

Control Requirements for Future Gas Turbine-Powered Unmanned Drones: JetQuads