Papers by Keyword: Power Law Model

Abstract: This study analyses physical aspects of power-law fluid flow over a diamond shaped cylinder under the impact of a movable screen fixed in the middle of a channel keeping an aspect ratio as 0.5 with height of the channel. The perforated plate is a screen at the middle especially settled at orientation of π/6, π/4 or π/3 degrees. The Reynolds number (Re) has been kept in the range of 1000-10,000 with power-law index in the range 0.8-1.2. For the corresponding two-dimensional problem, the governing momentum equations coupled with energy equation have been solved numerically using non-isothermal laminar fluid flow interface in the software COMSOL Multiphysics 5.4. The dimensionless velocity magnitude and the non-dimensional temperature on the diamond shaped cylinder along the vertical non-dimensional length are expressed via fixing any two parameters from (Re), angle of screen θ and power-law index. The heat transfer coefficient, effective thermal conductivity and the Nusselt number are also expressed besides the dimonsionless length of the surface of the chosen cylinder. In conclusion, we will be going to suggest points to increase the dynamics and thermal variables with the use of selected parameters Re, θ, and power law index n.

Abstract: In this work, the comparison between the Newtonian and the Power Law models was pointed out to determine the flow field within a system that includes the bypass of a narrowing zone (Stenosis) of an ideal artery. The simulations were conducted in a transient regime considering the pulsed effect inside the veins. The results show that the Power Law model does not sufficiently coincide with the Newtonian model, especially for describing the wall stresses. More specifically, the Power Law model predicts a velocity profile that remains parabolic for the entire time range analyzed, while the Newtonian model captures vorticities.

Abstract: The rheological properties of propellant are several key factors in the process design, which affect the quality of propellant processing that determines the weapon's performance. The main technological parameters influencing the quality of nitroguanidine-based propellant are nitroguanidine (NGu) content, solvent ratio and temperature. Rheological test of the propellant dough was carried out by using capillary rheometer. The effects of these main process parameters on the shear stress and shear viscosity of the propellant during the rheological process were discussed. Power law model, modified Bingham model and Cross model were used to fit the rheological data. The results show that Power law model is better than the other two models, explaining Power law model can be used as the constitutive equation to describe the actual rheological behavior of the propellant extrusion moulding more accurately.

Abstract: This paper investigates the finite element simulation to predict the creep response of Wood/PVC (WPVC) composite members before and after strengthening by using high carbon steel (HCS) flat bar strip adhered to the tension side. The creep parameters based on power law models of WPVC composites and the HCS flat bars were determined experimentally. Then, the nonlinear finite element analysis (FEA) software of ABAQUS was applied to predict the creep behaviors of composite members using the obtained experimentally creep parameters of individual component of WPVC composites and HCS flat bars. Good correlation between finite element simulation and experimental results are obtained for all cases. ABAQUS software with power law creep model show good potential for prediction the creep response of WPVC composites before and after strengthening.

Abstract: Power Law Model and Cross Model are widely used in Metal Powder Injection Molding computer simulation analysis. The feedstock viscosity data of Ti-6Al-4V is got through field tests, regression analysis is used to calculate the model parameters, which provides the theoretical basis for the application of computer simulation analysis in metal powder injection molding.

Abstract: Material constitutive equation plays an important role in Finite Element Analysis (FEA) of metal cutting process. This paper proposes a method to obtain parameters for Power Law model of a Japanese type of alloy steel (SCM440H) for 3-D FEA of face milling process, involving pressure bar experiments and orthogonal metal cutting experiments. Since pressure bar test cannot reach the high strain rate occurred in cutting process, orthogonal cutting experiment was combined to obtain parameters for material model. By this method, the ideal parameters for FEA of the face milling process were finally determined. Face milling experiments were performed to verify the accuracy of the model built.