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.

Application of the network equivalent concept for external system representation for power system transient analysis is well known. However, the challenge to utilize an equivalent network, approximated by a rational function, is to guarantee the passivity of the corresponding model. In this regard, special techniques are required to enforce the passivity of the equivalent model through a post processing approach that minimizes its impact on the original model characteristics. In this paper, the passivity is enforced by expressing the problem in terms of a convex optimization problem that guarantees the global optimal solution. The convex optimization problem is efficiently solved by recently developed numerical interior–point methods. This passivity enforcement is also global which indicates that the passivity enforcement in one region does not lead to passivity violation in other regions.

In this research, the continuous adjoint method is applied to optimize an airfoil in subsonic and transonic flows. An Euler flow solver is used to analyze the inviscid compressible flow over airfoils in each design cycle. Two design problems appearing in aerodynamic shape optimization, namely inverse pressure design and drag minimization were investigated. In the first part, a test case was carried out to evaluate the performance of the adjoint method in inverse design problem. The results show that we can use the adjoint method as an efficient tool in inverse aerodynamic design problems. In the second part, the constrained optimization was investigated in a drag minimization problem. The investigated samples show that a small variation of airfoil geometry has caused considerable decrease in the drag coefficient. To evaluate the performance of the adjoint method in design problems with numerous design variables and also to evaluate the effects of the adoption of the design vector on the optimization results, the constrained drag minimization was performed using two different design vectors. The results shows that the mechanism and the value of drag reduction are affected by the type of design vector. Also, computational cost of the adjoint method are independent of the number of design variables.

This paper presents an improved version of a recently developed evolutionary algorithm namely patchwork model. In order to decide which action (move or mate) must be performed by each agent, a new action selector is introduced that works based on the agent's memory. The actions of each agent and the sequence of applying them by the agent are revised to improve the effectiveness of the algorithm. Two types of movements are introduced that are called place movement and value movement. Also mate action is performed locally in each patch. Moreover, in order to exploit the search abilities as well as search speedup, search space is divided between patches. After every ten iterations, the predefined search regions for patches are more limited in terms of variables of the search space. On the other hand, non-informative search intervals are rejected by patches along with the progress of the search process. Finally, the performance of the algorithm is compared to the Gravitational Search Algorithm (GSA) over several well-known benchmark optimization functions. The obtained results show the effectiveness of the proposed algorithm in terms of the convergence rate and the quality of found solutions.

Different vehicle standards are used for decreasing of casualties for example the Protection of occupants of the CAB of a commercial vehicle. Vehicle manufacturer increase the power to weight ratio to achieve high speed vehicles. The optimization of the heavy vehicle’s cabin structure according to safety standards are important to achieve best function. In this article, the Mercedes Benz Actors is simulated in CATIA software. The model is meshed in Hyper-mesh software. The meshes are square and triangular and they are 10, 15 and 25 mm2. After checking truck's meshes, the model Import to LS-DYNA software. ECE-R29 test is performed in three parts include test B and test C. Test C includes two parts: 1-vertical collision and 2-collision with an angle of 20 degrees to the horizon. After the vehicle has successfully completed these tests, the most important parts in tests are identified. These parts are: 1. Side panel 2. Roof panel 3. A-pillar exterior 4. A-Pillar interior 5. Windshield upper panel. Then the thickness of parts are optimized. Only five modes of 16 modes (are submitted by the Taguchi method) are able to meet the requirements of the ECE-R29 B test. The optimal mode has a weight of 890.83 kg which has decreased 60.63kg compared to the initial mode.

In this research, in order to investigate the effect of the piezoelectric patch which is used as a sensor or actuator in rotating flexible structures such as a helicopter blade, the free vibrations of the rotating rectangular sheet with and without the piezoelectric patch have been presented. First-order shear deformation theory is considered for plate displacement and piezoelectric field. Considering the effect of Coriolis acceleration, centrifugal acceleration and centrifugal in-plane forces, the equations of motion are derived from Hamilton's principle and the electromechanical couple equation is obtained from Maxwell's equation. For piezoelectric, two electrical conditions, open circuit and closed circuit, which are used in sensors and actuators, respectively, have been considered. The equations are discretized with the help of the numerical method of generalized differential squares and the matrices of inertia mass, eccentricity, Coriolis and stiffness matrix are obtained. Natural frequency values for beam and rotating plate have been compared in Abaqus software. Also, the values obtained from the numerical solution in MATLAB have been verified with articles and ABAQUS, which have high accuracy. The effect of parameters such as hub radius, rotation speed, sheet thickness, aspect ratio, piezoelectric patch thickness and applied voltage on the natural frequency of the system has also been investigated.

Plastic hinge properties play a crucial role in predicting the nonlinear response of structural elements. The plastic hinge region of reinforced concrete normal beams has been previously studied experimentally and analytically. The main objective of this research is to evaluate the behavior of the plastic hinge region of reinforced concrete deep beams and its comparison with normal beams through finite element simulation. To do so, ten beams contain six deep beams, and four normal beams, under concentrated and uniformly distributed loading, are investigated. Lengths in the plastic hinge region involving curvature localization, rebar yielding, and concrete crushing zones are studied. The results indicate that the curvature localization zone is not suitable for the prediction of plastic hinge length in reinforced concrete deep beams. Based on the results it can be stated that in simply supported normal beams the concrete crushing zone is focused on the middle span, but in simply supported deep beams by creating a compression strut between loading place and support, the concrete crushing zone spreads along the compression trajectory. The rebar yielding zone of simply supported beams increases as the loading type is changed from the concentrated load at the middle to the uniformly distributed load.

Lithium-ion battery technology in the modern automotive industry utilizes highly temperature-sensitive batteries. Here, air cooling strategies will be the most applicable for the chosen example based on strategies for temperature control. Simulations have been utilized to evaluate the different thermal management strategies. A battery model was developed using the solutions offered by Computational Fluid Dynamics (CFD) simulation technology. It utilizes the heat produced by the discharge of the battery cells. Due to the simulation's limited computational capacity, the energy transfer model was implemented with a simplified but sufficiently complex physical mesh. Ten actual measurements were conducted in the laboratory to investigate the heating of the cell during the charging and discharging of 18650-type batteries. The results were applied to validate the simulation model. The simulation outcomes and thermal camera readings were compared. The cell-level numerical model was then extended to examine the temperature variation at the system level. The primary design objective is to achieve the highest energy density possible, which necessitates that the cells be constructed as closely as possible; however, increasing the distance between the cells can provide superior cooling from a thermal management perspective. The effect of varying the distance between individual cells on the system's heating was analyzed. Greater distance resulted in a more efficient heat transfer. It was also discovered that, in some instances, a small distance between cells produces inferior results compared to when constructed adjacently. A critical distance range has been established based on these simulations, which facilitates the placement of the cells.