Injection (moteur)

Résumé

L'injection est un dispositif d'alimentation des moteurs à explosion, permettant d'acheminer (directement ou un peu en amont) le carburant dans la chambre de combustion. Préférée au carburateur afin d'améliorer le rendement moteur, l'injection fut à l'origine exclusivement mécanique, puis améliorée par l'électronique en utilisant un calculateur électronique. Histoire Balbutiements Le premier moteur à explosion alimenté par un système d'injection est breveté en 1893 par l'ingénieur Rudolph Diesel. Les premières applications de l'injection sur les moteurs à explosion remontent aux années 1930. En Allemagne, Mercedes-Benz et Bosch mettent au point un système d'injection directe adapté aux moteurs d'avions comme celui du Me109. Durant la Seconde Guerre mondiale, les avions américains utilisent ce système, sur le principe de l'injection indirecte monopoint. Après la guerre, c'est en 1949 que les premiers moteurs à combustion interne sont alimentés par injection

Source officielle

https://fr.wikipedia.org/wiki/Injection_(moteur)

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In this work, a parametric study is done with computational methods for groundwater flow and heat transport in order to describe the dominant physical phenomena in an Aquifer Thermal Energy Storage (ATES). Optimum operating conditions and geological parameters are deduced from it. The intended use of the ATES is the domestic water or space heating. The stock is seasonal and functions without heat pump. Parametric study is organized as a series of reference simulations relating to the thickness of the aquifer and the injection flow rate. The other parameters and operating conditions of are kept constant. Other simulations are done and compared to the reference simulations in order to describe the influence of injection temperature, hydraulic conductivity, anisotropicity, injection frequencies, phases of rest, outflow rate and doublet wells. The cells of natural convection are strongly affecting the performances of an ATES. The thermal losses by conduction trough bedrock and caprock is an unfavourable factor as well, but to a lesser extent however. The increase of inflow rate always improves the efficiency, whereas an optimum aquifer thickness exists for each inflow rate. This optimum is characterised by weak natural convection phenomena. A greater thickness means strong density-viscosity effects, while a thinner aquifer forms a horizontally stretched stock, with increased conductive losses through the bedrock and cap rock. A maximum thermal recovery rate exists for a given flow rate. This maximum increases with inflow rate. The injection temperature behaves on the stock in the same way as the aquifer thickness for a given inflow: there is an optimal temperature. However it is in general preferable to increase the injection temperature instead of the inflow rate. In terms of optimization of the thermal power at disposal, the most favorable scenario is an increasing flow during the discharge. The precise scenario is different for each problem. The performances of a ATES are the complex result of the many parameters which enter in plays. One will recommend an inflow rate of at least 100m33/d during 6 months, and even rather 500 - 1000m3/d with an injection temperature of 80°C at least. An injection temperature of 60°C will have to be associated with an inflow of 1000m3/d at least. The geological targets proposed in Switzerland are the quaternary alluvial deposits filling the former glaciated valleys, fluvioglacial deposits and alluvial fans.

EPFL2001

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Water Injection in isothermal co-rotating scroll compressor and turbine

Roberto Passini

This project deals with the study of a quasi-isothermal scroll compression/expansion obtained by spray injection of water. The spray injection process is first described from the theoretical point of view as it concerns the droplets formation and breakup processes, both directly related to the evaporation. A simulation of spray injection is also performed using Ansys CFX. The last part deals with an experimental application in the laboratory of the system studied. Results are presented and discussed both for CFD simulation and experimental part.

2012

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T Cells Redirected to a Minor Histocompatibility Antigen Instruct Intratumoral TNF alpha Expression and Empower Adoptive Cell Therapy for Solid Tumors

Melody Swartz

Donor-derived allogeneic T cells evoke potent graft versus tumor (GVT) effects likely due to the simultaneous recognition of tumor-specific and host-restricted minor histocompatibility (H) antigens. Here we investigated whether such effects could be reproduced in autologous settings by TCR gene-engineered lymphocytes. We report that T cells redirected either to a broadly expressed Y-encoded minor H antigen or to a tumor-associated antigen, although poorly effective if individually transferred, when simultaneously administered enabled acute autochthonous tumor debulking and resulted in durable clinical remission. Yredirected T cells proved hyporesponsive in peripheral lymphoid organs, whereas they retained effector function at the tumor site, where in synergy with tumor-redirected lymphocytes, they instructed TNFa expression, endothelial cell activation, and intratumoral T-cell infiltration. While neutralizing TNFa hindered GVT effects by the combined T-cell infusion, a single injection of picogram amounts of NGR-TNF, a tumor vessel-targeted TNF alpha derivative currently in phase III clinical trials, substituted for Y-redirected cells and enabled tumor debulking by tumor-redirected lymphocytes. Together, our results provide new mechanistic insights into allogeneic GVT, validate the importance of targeting the tumor and its associated stroma, and prove the potency of a novel combined approach suitable for immediate clinical implementation. (C) 2016 AACR.

Amer Assoc Cancer Research2017

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EPFL2001