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Pre-swirl systems are important components for the internal cooling of turbomachinery. They allow to reduce the total relative temperature of the rotor disc and blades by feeding the rotor with a fast and tangential air. The gases exiting the combustion chamber can therefore have higher temperature, thus, increasing the overall efficiency of the turbomachinery. 
This thesis aims at investigating a new design of pre-swirl system from a jet engine high pressure turbine (HPT) core made with additive manufacturing (AM). Indeed, additive manufacturing presents many assets for the aeronautic industry as it offers new possibilities in terms of design while reducing the component mass. The study consists in 3D CFD analysis on Fluent for steady take-off operating conditions. The thermal, aerodynamic, integration and additive manufacturing requirements related to pre-swirl systems are detailed. This led to a pre-swirl system with a curved nozzle and a house shape cross section. Different geometry influence studies are conducted to investigate the new design. The influence of surface ratio between the nozzle inlet and throat surfaces and reduced radius R are examined. An air intake device (AID) located at the inlet of the nozzle is also studied. The configurations are compared to the radial pre-swirl system with vane nozzles of a HP turbine core representing the baseline configuration. The flow performances are evaluated in terms of outlet mass flow, discharge coefficient, throat Mach number and nozzle outlet swirl ratio. 
As preliminary results, the impact of the sub-chamber upstream of the pre-swirl system is studied. The transition between this chamber and the pre-swirl system can be assimilated to an elbow duct. This elbow duct introduces turbulences leading to performance losses. The influence studies have shown that a high surface ratio and a low reduced radius offer the best flow performances. Furthermore, the AID device reduces the losses at the nozzle inlet improving the performances. 
The comparison of all the AM nozzle configuration has shown that the configuration with the highest performances is R=0.2 with AID. However, the current AID design introduces mass to the assembly and doesn’t improve significantly the flow performances for low reduced radius configuration. Therefore, the selected optimum configuration is R=0.2 without AID. This configuration has a lower mass from 30% compared to the baseline configuration. However, in terms of flow performances, it shows lower results compared to the baseline configuration, especially for the Mach number and swirl ratio.

pre-swirl system --- aerodynamics --- thermal --- jet engine --- turbomachinery --- CFD --- Ingénierie, informatique & technologie > Ingénierie aérospatiale

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With the advances in high-speed computer technology, complex heat transfer and fluid flow problems can be solved computationally with high accuracy. Computational modeling techniques have found a wide range of applications in diverse fields of mechanical, aerospace, energy, environmental engineering, as well as numerous industrial systems. Computational modeling has also been used extensively for performance optimization of a variety of engineering designs. The purpose of this book is to present recent advances, as well as up-to-date progress in all areas of innovative computational heat transfer and fluid mechanics, including both fundamental and practical applications. The scope of the present book includes single and multiphase flows, laminar and turbulent flows, heat and mass transfer, energy storage, heat exchangers, respiratory flows and heat transfer, biomedical applications, porous media, and optimization. In addition, this book provides guidelines for engineers and researchers in computational modeling and simulations in fluid mechanics and heat transfer.

Technology: general issues --- History of engineering & technology --- auxiliary feedwater system --- cavitation --- computational fluid dynamics --- in-service testing --- multiphase flow --- multi-stage orifice --- nonuniform metal foam --- melting heat transfer --- thermal energy storage --- conical swirl atomizer --- atomization --- CFD --- Eulerian model --- heat transfer coefficient --- micro-fins --- friction factor --- numerical methods --- micro- and macro-parameters of the atomized liquid --- mechanism of effervescent-swirl atomization --- efficiency of atomization process --- effervescent-swirl atomizer --- fixed-bed reactor --- wall structures --- complex particle shapes --- process intensification --- heat transfer --- photovoltaic cell efficiency --- thermal regulation --- energy and light harvesting --- irreversibility losses --- quantum dynamics --- nature-inspired mimicking --- heat transfer enhancement --- radiation insert --- numerical simulations --- performance evaluation criteria --- thermal efficiency --- particle sedimentation --- resistance force --- fractional-order integro-differential equation --- laplace transform --- Mittag–Leffler function --- block-pulse operational matrix --- Nu number --- microchannel heat sink --- trefoil ribs --- thermal enhancement --- thermal resistance --- triple-tube heat exchanger --- twisted fin array --- phase change material --- solidification --- nanofluids advantages and disadvantages --- thermal hydraulic performance --- vortex generators --- micro-channel

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With the advances in high-speed computer technology, complex heat transfer and fluid flow problems can be solved computationally with high accuracy. Computational modeling techniques have found a wide range of applications in diverse fields of mechanical, aerospace, energy, environmental engineering, as well as numerous industrial systems. Computational modeling has also been used extensively for performance optimization of a variety of engineering designs. The purpose of this book is to present recent advances, as well as up-to-date progress in all areas of innovative computational heat transfer and fluid mechanics, including both fundamental and practical applications. The scope of the present book includes single and multiphase flows, laminar and turbulent flows, heat and mass transfer, energy storage, heat exchangers, respiratory flows and heat transfer, biomedical applications, porous media, and optimization. In addition, this book provides guidelines for engineers and researchers in computational modeling and simulations in fluid mechanics and heat transfer.

Technology: general issues --- History of engineering & technology --- auxiliary feedwater system --- cavitation --- computational fluid dynamics --- in-service testing --- multiphase flow --- multi-stage orifice --- nonuniform metal foam --- melting heat transfer --- thermal energy storage --- conical swirl atomizer --- atomization --- CFD --- Eulerian model --- heat transfer coefficient --- micro-fins --- friction factor --- numerical methods --- micro- and macro-parameters of the atomized liquid --- mechanism of effervescent-swirl atomization --- efficiency of atomization process --- effervescent-swirl atomizer --- fixed-bed reactor --- wall structures --- complex particle shapes --- process intensification --- heat transfer --- photovoltaic cell efficiency --- thermal regulation --- energy and light harvesting --- irreversibility losses --- quantum dynamics --- nature-inspired mimicking --- heat transfer enhancement --- radiation insert --- numerical simulations --- performance evaluation criteria --- thermal efficiency --- particle sedimentation --- resistance force --- fractional-order integro-differential equation --- laplace transform --- Mittag–Leffler function --- block-pulse operational matrix --- Nu number --- microchannel heat sink --- trefoil ribs --- thermal enhancement --- thermal resistance --- triple-tube heat exchanger --- twisted fin array --- phase change material --- solidification --- nanofluids advantages and disadvantages --- thermal hydraulic performance --- vortex generators --- micro-channel

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The collection of articles discussed above covers various types of discharges and various processes. The discharges presented include, for example, microwave, spark, glow or surface discharges. The characterizations of the sources of these discharges, the parameters of the generated plasmas as well as the applications of these plasmas are discussed. The applications include, for example, the synthesis of nanoparticles or the treatment of skin cancer cells. I hope that the presented articles will be valuable for readers representing the world of science, medicine and technology.

Research & information: general --- Biology, life sciences --- Biochemistry --- surface discharge --- epoxy resin --- electronegative gas --- high-voltage power equipment --- diffusion welding --- plasma --- glow discharge --- surface treatment --- plasma techniques --- spark discharge --- nanoparticle synthesis --- silver electrodes --- electrodes asymmetry --- vortex break down --- plasma swirl injector --- dielectric barrier discharge --- swirling flow control --- melanoma cell (B16F10) --- plasma cancer therapy --- cold atmospheric plasma (CAP) --- transferred cold atmospheric plasma --- reactive oxygen species (ROS) --- reactive nitrogen species (RNS) --- catalase --- microwave plasma --- dual-frequency plasma --- electron temperature --- electron density --- n/a

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The collection of articles discussed above covers various types of discharges and various processes. The discharges presented include, for example, microwave, spark, glow or surface discharges. The characterizations of the sources of these discharges, the parameters of the generated plasmas as well as the applications of these plasmas are discussed. The applications include, for example, the synthesis of nanoparticles or the treatment of skin cancer cells. I hope that the presented articles will be valuable for readers representing the world of science, medicine and technology.

surface discharge --- epoxy resin --- electronegative gas --- high-voltage power equipment --- diffusion welding --- plasma --- glow discharge --- surface treatment --- plasma techniques --- spark discharge --- nanoparticle synthesis --- silver electrodes --- electrodes asymmetry --- vortex break down --- plasma swirl injector --- dielectric barrier discharge --- swirling flow control --- melanoma cell (B16F10) --- plasma cancer therapy --- cold atmospheric plasma (CAP) --- transferred cold atmospheric plasma --- reactive oxygen species (ROS) --- reactive nitrogen species (RNS) --- catalase --- microwave plasma --- dual-frequency plasma --- electron temperature --- electron density --- n/a