15. 11. 2013. Seminar: Igor Stanković

Friday, 15 November 2013 at 2:00 PM, IPB Library

seminar organised by Scientific Computing Laboratory

Igor Stanković
Scientific Computing Laboratory, Institute of Physics Belgrade

Мolecular dynamics simulation investigation of fuel droplet in evolving ambient conditions

Abstract:

In the first part of the lecture an overview will be given of principal processes taking place in cylinder of an internal combustion engine. Also, current efforts and methods used for engine efficiency improvement research will be presented - with special attention on simulation methods and challenges of chemical reaction introduction into computational fluid dynamics. In the second part of the lecture non-equilibrium molecular dynamics simulations will be presented of fuel droplet surrounded by air in a spatially and temporally evolving environment. A numerical procedure is developed to include chemical reactions into molecular dynamics. The model reaction is chosen to allow investigation of the position of chemical reactions and the behavior of typical products (alcohols and aldehydes). A liquid droplet at molecular scale is seen as a network of fuel molecules interacting with oxygen, nitrogen, and products of chemical fuel breakdown. A molecule is evaporating when it loosens from the network and diffuses into the air. Naturally, fuel molecules from the gas phase, oxygen and nitrogen molecules can also be adsorbed in the reverse process into the liquid phase. Thus, in the presented simulations the time and length scales of transport processes – oxygen adsorption, diffusion, and fuel evaporation are directly determined by molecular level processes and not by model constants.