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.

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.

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.

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 Analysis and Pareto Frontier Based Tradeoff Design of an Integrated Magnetic Structure for a CLLC Resonant Converter

Energies ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1756
Author(s):  
Gang Wang ◽  
Qiyu Hu ◽  
Chunyu Xu ◽  
Bin Zhao ◽  
Xiaobao Su
Keyword(s):  
Magnetic Structure ◽  
Power Density ◽  
High Efficiency ◽  
Pareto Frontier ◽  
Optimization Procedure ◽  
Magnetic Core ◽  
Pareto Optimization ◽  
High Power Density ◽  
Resonant Converter ◽  
Conduction Loss

This paper proposes an integrated magnetic structure for a CLLC resonant converter. With the proposed integrated magnetic structure, two resonant inductances and the transformer are integrated into one magnetic core, which improves the power density of the CLLC resonant converter. In the proposed integrated magnetic structure, two resonant inductances are decoupled with the transformer and can be adjusted by the number of turns in each inductance. Furthermore, two resonant inductances are coupled to reduce the number of turns in each inductance. As a result, the conduction loss can be reduced. The trade-off design of the integrated magnetic structure is carried out based on the Pareto optimization procedure. With the Pareto optimization procedure, both high efficiency and high-power density can be achieved. The proposed integrated magnetic structure is validated by theoretical analysis, simulations, and experiments.

scholarly journals Near-field thermophotovoltaics for efficient heat to electricity conversion at high power density

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Rohith Mittapally ◽  
Byungjun Lee ◽  
Linxiao Zhu ◽  
Amin Reihani ◽  
Ju Won Lim ◽  
...  
Keyword(s):  
Power Density ◽  
High Power ◽  
High Efficiency ◽  
Near Field ◽  
Electrical Power ◽  
Photovoltaic Cells ◽  
High Power Density ◽  
Pv Cell ◽  
Electrical Power Output ◽  
Power Densities

AbstractThermophotovoltaic approaches that take advantage of near-field evanescent modes are being actively explored due to their potential for high-power density and high-efficiency energy conversion. However, progress towards functional near-field thermophotovoltaic devices has been limited by challenges in creating thermally robust planar emitters and photovoltaic cells designed for near-field thermal radiation. Here, we demonstrate record power densities of ~5 kW/m2 at an efficiency of 6.8%, where the efficiency of the system is defined as the ratio of the electrical power output of the PV cell to the radiative heat transfer from the emitter to the PV cell. This was accomplished by developing novel emitter devices that can sustain temperatures as high as 1270 K and positioning them into the near-field (<100 nm) of custom-fabricated InGaAs-based thin film photovoltaic cells. In addition to demonstrating efficient heat-to-electricity conversion at high power density, we report the performance of thermophotovoltaic devices across a range of emitter temperatures (~800 K–1270 K) and gap sizes (70 nm–7 µm). The methods and insights achieved in this work represent a critical step towards understanding the fundamental principles of harvesting thermal energy in the near-field.

High-Power-Density High-Efficiency Bottom-Emitting Vertical-Cavity Surface-Emitting Laser Array

2011 ◽  
Vol 4 (5) ◽  
pp. 052104 ◽  
Author(s):  
Di Liu ◽  
Yongqiang Ning ◽  
Yugang Zeng ◽  
Li Qin ◽  
Yun Liu ◽  
...  
Keyword(s):  
Power Density ◽  
High Power ◽  
High Efficiency ◽  
Cavity Surface ◽  
High Power Density ◽  
Laser Array ◽  
Vertical Cavity Surface ◽  
Surface Emitting Laser ◽  
Vertical Cavity
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