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Full-Text Articles in Mechanical Engineering
Droplet Evaporation And Deformations In An Amplitude Modulated Ultrasonic Field, Nihad E. Daidzic, Rene Stadler, Adrian Melling
Droplet Evaporation And Deformations In An Amplitude Modulated Ultrasonic Field, Nihad E. Daidzic, Rene Stadler, Adrian Melling
Aviation Department Publications
The aim of the report presented is the measurements of droplet oscillations.
A New Spray Evaporation Model Based On Droplet Interface Phenomena, Nihad E. Daidzic, Gangolf Kohnen, Martin Sommerfeld
A New Spray Evaporation Model Based On Droplet Interface Phenomena, Nihad E. Daidzic, Gangolf Kohnen, Martin Sommerfeld
Aviation Department Publications
In this work the influence of droplet shape oscillations on droplet evaporation is shown. Through nonlinear mode interactions, turbulence and aerodynamic triggering of vibrations cause by vortex shedding, droplets always oscillates in spray flows. Droplet shape oscillation cause higher evaporation rates through several physical phenomena such as an average increase of the superficial surface area, periodic micro-convection and boundary layer destruction, and local saturation pressure changes due to local curvature effects. The inviscid theory of small-amplitude droplet oscillations was used which resulted in better agreement with the measurement data of droplet size distributions in sprays for different axial coordinates.
A Mathematical Model And Simulation Of Natural Circulation Loop Thermalhydraulics, Nihad E. Daidzic
A Mathematical Model And Simulation Of Natural Circulation Loop Thermalhydraulics, Nihad E. Daidzic
Aviation Department Publications
In this work, a simple, nonlinear, seventh-order mathematical model with lumped parameter analysis of the thermalhydraulic processes in a natural circulation steam boiler loop is presented. Digital simulation has been performed in order to predict open loop transients in severe accidental situations. Parts of the circulation loop such as the steam drum, downcomer, and riser were modelled separately on the basis of the integral balance equations. The two-phase flow in the steam drum and in the riser was modelled with the aid of a homogeneous-equilibrium, two-phase flow model. Special care was taken to ensure the stability of the numerical scheme, …