High-Efficiency, Lightweight, Flexible Solar Sheets with Very High Specific Power for Solar Flight

2018 ◽  
Author(s):  
R. Chan ◽  
M. Osowski ◽  
A. Wibowo ◽  
D. Cardwell ◽  
A. Kirk ◽  
...  
Keyword(s):  
High Efficiency ◽  
Specific Power ◽  
High Specific Power ◽  
Very High

The Isoengine: A Novel High Efficiency Engine With Optional Compressed Air Energy Storage (CAES)

2003 ◽  
Author(s):  
Claus Linnemann ◽  
Mike W. Coney ◽  
Anthony Price
Keyword(s):  
Energy Storage ◽  
Power Output ◽  
High Efficiency ◽  
Compressed Air ◽  
Specific Power ◽  
Small Scale ◽  
Compressed Air Energy Storage ◽  
Power Cycle ◽  
Specific Power Output ◽  
High Specific Power

A novel high efficiency reciprocating piston engine — the isoengine — is predicted to achieve net electrical efficiencies of up to 60% in units of 5 to 20 MWe size. The high efficiency and at the same time a high specific power output are achieved by integrating isothermal compression, recuperative preheating and isobaric combustion into a novel power cycle. The isoengine can utilize distillate oil, natural gas or suitable biofuels. While the first commercial isoengine is envisaged to have a power output of 7 MW, a 3 MW prototype engine is currently being tested. Since compression and combustion are performed in different cylinders, these processes can also be performed at different times such that the isoengine can be used to create a highly efficient small-scale compressed air energy storage (CAES) system. In such configuration, the engine can operate at more than 140% nominal load for a limited time, which depends on the air storage capacity.

The Development of Cost Effective Gas Turbine Installations Offshore

1994 ◽  
Author(s):  
William P. Hancock
Keyword(s):  
Gas Turbine ◽  
North Sea ◽  
Heat Recovery ◽  
High Efficiency ◽  
Cost Effective ◽  
Operating Costs ◽  
Specific Power ◽  
Aero Engine ◽  
Turbine Installation ◽  
Very High

The paper describes the application and development of the offshore gas turbine from its infancy on Lake Maracaibo, Venezuela up to the current mature technology. North Sea developments are described, particularly in the Norwegian sector which was an important contributor to advancing the state of the art. The first application of the second generation aero engine and of the very high pressure centrifugal gas compressor were important milestones which have made significant contributions to the economic recovery of North Sea hydrocarbons. The author describes the current efforts to further optimise gas turbine installation, and operating costs. Cheaper and lighter gas turbine facilities require, not only increases in specific power, but also considerable innovation from the Engineers responsible for the application of this machinery. For the future, fewer units of even larger ratings are foreseen, applied as high efficiency simple cycles with limited heat recovery.

scholarly journals Humid Air Gas Turbine Cycle: A Possible Optimization

1993 ◽  
Author(s):  
S. S. Stecco ◽  
U. Desideri ◽  
N. Bettagli
Keyword(s):  
Relative Humidity ◽  
Water Consumption ◽  
Compression Ratio ◽  
High Efficiency ◽  
Power Production ◽  
Specific Power ◽  
Humid Air ◽  
Air Turbine ◽  
High Specific Power ◽  
Gas Turbine Cycle

The humid air turbine (HAT), patented by Fluor Daniel, is an innovative cycle which allows to obtain an increase in efficiency and power production. The modification proposed by DEF allows to optimise the plant when natural gas is injected in the combustion chamber. Assuming a TIT (Temperature Inlet Turbine) at 1273 K and the cooling of recirculating water in the refrigerators, we studied the effects of the relative humidity and the compression ratio on the cycle’s performances. The aim of this paper is to suggest the parameters which allow to obtain high efficiency with high specific power, the possibility to modulate power production without a decrease in efficiency and low water consumption.

Modeling and Design of Air Vane Motors for Minimal Torque Ripples

2012 ◽  
Vol 134 (5) ◽  
Author(s):  
Cheng-Wei Cheng ◽  
Chao-Chieh Lan ◽  
Chun-Yi Tseng
Keyword(s):  
Numerical Optimization ◽  
Specific Power ◽  
Analysis And Design ◽  
Constant Torque ◽  
Rotary Machines ◽  
High Specific Power ◽  
Torque Curve ◽  
Profile Design ◽  
Torque Ripples ◽  
Very High

This paper presents the analysis and design of a novel air vane motor. Air motors have a very high specific power. They require compressed air rather than electricity to produce motion; thus, they avoid sparks and can be used in demanding environments. Similar to other types of rotary machines, air vane motors exhibit torque fluctuations. The varying torque curve is a result of unmatched torques generated by the vanes in one revolution. Accompanying the torque fluctuations are dynamic speed ripples that produce undesirable vibration on the load side. Rather than using auxiliary flywheels or dampers to smoothen the fluctuation, we propose a new motor with noncircular stator profile so as to increase the flexibility of balancing vane torques. Through numerical optimization of the parametric noncircular profile, a nearly constant torque curve can be achieved. Experiments validate that the speed ripples are greatly suppressed without compromising performance, when compared with traditional air vane motors that employ circular stator profiles. We expect that the noncircular stator profile design can be applied to air vane motors of various sizes to minimize torque and speed ripples.

scholarly journals Thermal Management of High-Power Density Electric Motors for Electrification of Aviation and Beyond

Energies ◽  
2019 ◽  
Vol 12 (19) ◽  
pp. 3594 ◽  
Author(s):  
David C. Deisenroth ◽  
Michael Ohadi
Keyword(s):  
Thermal Management ◽  
High Efficiency ◽  
Synchronous Machines ◽  
Specific Power ◽  
High Power Density ◽  
Electric Motors ◽  
Innovative Design ◽  
High Specific Power ◽  
Manufacturing Techniques ◽  
Cost Metrics

Enhanced cooling, coupled with novel designs and packaging of semiconductors, has revolutionized communications, computing, lighting, and electric power conversion. It is time for a similar revolution that will unleash the potential of electrified propulsion technologies to drive improvements in fuel-to-propulsion efficiency, emission reduction, and increased power and torque densities for aviation and beyond. High efficiency and high specific power (kW/kg) electric motors are a key enabler for future electrification of aviation. To improve cooling of emerging synchronous machines, and to realize performance and cost metrics of next-generation electric motors, electromagnetic and thermomechanical co-design can be enabled by innovative design topologies, materials, and manufacturing techniques. This paper focuses on the most recent progress in thermal management of electric motors with particular focus on electric motors of significance to aviation propulsion.

CFD and Thermomechanical Analysis on Effect of Curved Surface in IC Engine Cylinder Head

2016 ◽  
Vol 852 ◽  
pp. 739-746
Author(s):  
S. Balaji ◽  
Sarat Unnithan ◽  
A. Kumarasamy
Keyword(s):  
Heat Transfer ◽  
Cylinder Head ◽  
High Efficiency ◽  
Field Analysis ◽  
Curved Surface ◽  
Specific Power ◽  
Combustion Heat ◽  
Ic Engine ◽  
Engine Cylinder ◽  
High Specific Power

Next generation IC engines are designed to achieve high efficiency and high specific power. As a single most design drivingfactor, combustion pressure is increased more than before. This has major impact on the design aspects of cylinder head. Its featuresbecome more delicate to accommodate various elements. Thermal aspects composing of heat generation (by combustion); heat transfer(combustion, cooling water, intake and exhaust gas) makes the design more challenging. Methods to enhance the heat transfer andcontrolling body temperature are discussed by various authors. In this paper a high specific power engine cylinder head is analysedusing coupled field analysis. To enhance heat transfer, inner flame deck surface is configured as a curved surface instead of flat presentin the conventional cylinder heads. Effect of reduction in the cross sectional area due to curvature is analysed against flat surface. It isfound that this new approach reduces the flame deck temperature considerably without compromising the structural strength factors.CFD, steady state thermal and structural analysis has been carried out for four different cases to conclude the extend of effectivenessdue to curvature.

scholarly journals Near quantitative synthesis of urea macrocycles enabled by bulky N-substituent

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Yingfeng Yang ◽  
Hanze Ying ◽  
Zhixia Li ◽  
Jiang Wang ◽  
Yingying Chen ◽  
...  
Keyword(s):  
High Efficiency ◽  
Molecular Structures ◽  
High Yield ◽  
Kinetic Control ◽  
High Concentration ◽  
Weak Association ◽  
Quantitative Synthesis ◽  
Thermodynamic Stabilization ◽  
Discrete Structures ◽  
Very High

AbstractMacrocycles are unique molecular structures extensively used in the design of catalysts, therapeutics and supramolecular assemblies. Among all reactions reported to date, systems that can produce macrocycles in high yield under high reaction concentrations are rare. Here we report the use of dynamic hindered urea bond (HUB) for the construction of urea macrocycles with very high efficiency. Mixing of equal molar diisocyanate and hindered diamine leads to formation of macrocycles with discrete structures in nearly quantitative yields under high concentration of reactants. The bulky N-tert-butyl plays key roles to facilitate the formation of macrocycles, providing not only the kinetic control due to the formation of the cyclization-promoting cis C = O/tert-butyl conformation, but also possibly the thermodynamic stabilization of macrocycles with weak association interactions. The bulky N-tert-butyl can be readily removed by acid to eliminate the dynamicity of HUB and stabilize the macrocycle structures.

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