This article discusses the stagnation of an evolutionary optimization algorithm called Differential Evolution. Stagnation problem refers to a situation in which the optimum seeking process stagnates before finding a globally optimal solution. Typically, stagnation occurs virtually without any obvious reason. The stagnation differs from the premature convergence so that the population remains di...

In this paper we describe the design and operating characteristics of a computercontrolled four-roll mill for investigations of particle and drop dynamics in twodimensional linear flows. The control system is based upon the use of: a video camera to visualize the instantaneous position of the drop or particle ; a PDP 11/23 computer, with a pipeline processor acting as an interface between the c...

Convergence of multigrid and defect-correction iterations is comprehensively studied within different incompressible and compressible inviscid regimes on high-density grids. Good smoothing properties of the defectcorrection relaxation have been shown using both a modified Fourier analysis and a more general idealizedcoarse-grid analysis. Single-grid defect correction alone has some slowly conve...

The paper deals with a stagnation-point boundary layer flow towards a permeable stretching/shrinking sheet in a nanofluid where the flow and the sheet are not aligned. We used the Buongiorno model that is based on the Brownian diffusion and thermophoresis to describe the nanofluid in this problem. The main purpose of the present paper is to examine whether the non-alignment function has the eff...

A numerical model was developed to predict gas-phase nucleation of particles during silane pyrolysis. The model includes a detailed clustering mechanism for the formation of hydrogenated silicon clusters containing up to ten silicon atoms. This mechanism was coupled to an aerosol dynamics moment model to predict particle growth, coagulation, and transport. Both zero-dimensional transient simula...

Unsteady simulations of stagnation point flames are conducted in order to study flame turbulence interactions in a relatively simple flow environment. Flame propagation is represented using a flamelet model called the G equation. Two subgrid models are used to close the filtered G equation. The effects of significant heat release on the turbulent flow and the effect of varying turbulence intens...

In this part of the investigation, flow-field properties of hydrogen jets injected into a hypersonic flow are reported. The combustor has a single fuel injection parallel to the main flow from the base. The numerical simulation has been done with finite rate chemistry model using K-ε turbulence model. The results obtained through the numerical simulation of the cavity based fuel injectors are p...

Dysmenorrhea is one of the most common gynecologic complain, especially among young women. It influences daily activities, and lowers life quality. In clinical practice, non-steroidal antiinflammatory drugs (NSAIDs) are used as the firstline treatment for dysmenorrhea. However, longterm use of these medications is associated with side effects. Some Chinese herbal medicines (CHMs) were reported ...

Divalent cationic strontium (Sr2~-l adsorption to and desorption from iron corrosion products were examined in two model drinking water distribution systems (DWDS). One system was maintained with chlorine-disinfected drinking water and the other with the same water with secondary chloramine disinfection. Flow conditions simulated primary transmission lines (constant flow) and residential mains ...

The present research investigated the role of blood viscosity on flow within a microvascular network to identify the conditions of blood flow stagnation. When the yield stress of blood was less than 0.005 Pa, there were no stagnant regions in the microvasculature. However, when the yield stress increased to 0.05 Pa, stagnant or reduced flow areas began to appear, which grew and expanded rapidly...