In this paper, recommended spiral passive micromixer was designed and simulated. spiral design has the potential to create and strengthen the centrifugal force and the secondary flow. A series of simulations were carried out to evaluate the effects of channel width, channel depth, the gap between loops, and flowrate on the micromixer performance. These features impact the contact area of the two fluids and ultimately lead to an increment in the quality of the mixture. In this study, for the flow rate of 25 μl/min and molecular diffusion coefficient of 1×10-10 m2/s, mixing efficiency of more than 90% is achieved after 30 (approximately one-third of the total channel length). Finally, the optimized design fabricated using proposed 3D printing method.

A computational technique for solution of mathematical model of gas solution in a fluid is presented. This model describes the change of mass of the gas volume due to diffusion through the contact surface. An appropriate representation of the solution based on the Mü ntz polynomials reduces its Numerical treatment to the solution of a linear system of algebraic equations. Numerical examples are given and discussed to illustrate the effectiveness of the proposed approach.

In this paper, we consider an inverse heat condition problem. the given heat condition equation, the boundary condition, and the initial condition are presented in a dimensionless form. a set of temperature measurement at a single sensor location inside the heat conduction body is required. The existence, unicity, and stability of the solution to this inverse heat conduction problem will be shown.

In this paper, we use a third degree B-spline function to construct an approximate solution for third order linear and nonlinear boundary value problems coupled with the least square method. Several examples are given to illustrate the efficiency of the proposed technique.