Suggesting a full two level experimental factorial model with three factors to optimize Ti-HA biocomposite properties

A metal matrix composites (MMCs) is introduced to serve as synthetic bone grafts. The MMC was synthetized via powder metallurgical method after milling raw powder mixture of hydroxyapatite (HA) particles and pure titanium (Ti) powder. A full two level experimental factorial model with three factors (2^3) was developed to study the effect of three main parameters of synthetizing process on the hardness, density, and crystallite size of the composite. The synthetizing process parameters under consideration were the mechanical alloying time as well as the ceramic powder initial size and its mass fraction in the mixed powder. The results demonstrate that the composite’s hardness is increasing with higher HA mass fraction (W/W) of the composite and longer milling time. The analysis of data also show that the initial HA particle size has insignificant influence on the composite’s hardness, while higher HA content fraction in the MMC decreases the density of the composite

Geometric parameters and response surface methodology on cooling performance of vortex tubes

This research has investigated the effect of certain geometric parameters on cooling performance of three vortex tubes. The influencing parameters include three length/diameter ratios L/D = 10, 25, 40, three nozzle cases and each case with number n = 2, 4, 6 nozzles, three cold orifice/diameter ratios β = 0.389, 0.5, 0.611 and three inlet pressures Pi = 2, 2.5 and 3 bar. The experiments are conducted based on three factors, two-level and central composite face-centred design with full factorial. The results are analysed according to the principle of response surface methodology. The goodness of fit of the regression model is inspected using the analysis of variance and F-ratio test. The values of R2 and R2-adjusted are close to 100% which show a very good correlation between the observed and predicted values. The results show that the effect of number of nozzles on the energy separation depends on the L/D values

Control of flow around a circular cylinder wrapped with a porous layer by magnetohydrodynamic

The present study focuses on the analysis of two-dimensional Magnetohydrodynamic (MHD) flow past a circular cylinder wrapped with a porous layer in different laminar flow regimes. The Darcy-Brinkman-Forchheimer model has been used for simulating flow in porous medium using finite volume based software, Fluent 6.3. In order to analyze the MHD flow, the mean and instantaneous drag and lift coefficients and stream patterns are computed to elucidate the role of Stuart number, N and Darcy number, Da. It is revealed that the magnetic fields are capable to stabilize flow and suppress the vortex shedding of vortices. The N-Re plane shows the curves for separating steady and periodic flow regimes, Ncr and disappearing of vortex, Ndiss. For validate the solution, the obtained CD and St are compared with available results of literature

Control of flow around a circular cylinder wrapped with a porous layer by magnetohydrodynamic

The present study focuses on the analysis of <i>two-dimensional Magnetohydrodynamic (MHD)</i> flow past a circular cylinder wrapped with a porous layer in different laminar flow regimes. The <i>Darcy-Brinkman-Forchheimer</i> model has been used for simulating flow in porous medium using finite volume based software, Fluent 6.3. In order to analyze the <i>MHD</i> flow, the mean and instantaneous drag and lift coefficients and stream patterns are computed to elucidate the role of Stuart number, <i>N</i> and <i>Darcy number, Da</i>. It is revealed that the magnetic fields are capable to stabilize flow and suppress the vortex shedding of vortices. The <i>N-Re</i> plane shows the curves for separating steady and periodic flow regimes, <i>Ncr</i> and disappearing of vortex, <i>Ndiss</i>. For validate the solution, the obtained <i>CD</i> and <i>St</i> are compared with available results of literature