| Autor: |
Meingast, U, Reichelt, L, Renz, U |
| Předmět: |
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| Zdroj: |
International Journal of Engine Research (Professional Engineering Publishing); Oct2004, Vol. 5 Issue 5, p443-452, 10p, 3 Diagrams, 12 Graphs |
| Abstrakt: |
Droplet break-up and evaporation processes in small-bore direct injection combustion engines may be influenced by the contact between the liquid spray and the engine wall surfaces. In this work, experimental data are presented that may be used to validate spray models and computational fluid dynamics (CFD) codes commonly employed in internal combustion engine design processes. For the investigation, a high-pressure high-temperature injection chamber equipped with a common-rail injection system is used in combination with a heated wall aligned normal to the spray. The test conditions represent moderate diesel engine conditions. The temperature data of three surface thermocouples, which resolve the transient temper- ature of the wall, are numerically processed to evaluate the surface wall heat flux from an analytical solution of the transient energy equation. The spray impinging on the surface causes a fast tem- perature change of up to 10 K in the stagnation region. The calculated surface heat flux exceeds 106 W/m2. The maximum flux, which is detected at the centre, increases as the distance between the wall and the injector is decreased or the wall temperature is increased. At larger wall distances and low wall temperatures no significant heat flux can be detected. The data of phase Doppler anemometry measure- ments conducted under identical conditions correlates well with the heat flux measurements. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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