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.

Discrete-event simulation based optimization is the process of finding the optimum design of a stochastic system when the performance measure(s) could only be estimated via simulation. Randomness in simulation outputs often challenges the correct selection of the optimum. We propose an algorithm that merges Ranking and Selection procedures with a large class of random search methods for continuous simulation optimization problems. Under a mild assumption, we prove the convergence of the algorithm in probability to a global optimum. The new algorithm addresses the noise in simulation outputs while benefits the proven efficiency of random search methods.

This paper present simulation-optimization models for waste load allocation from multiple point sources which include uncertainty due to vagueness of the parameters and goals. This model employs fuzzy sets with appropriate membership functions to deal with uncertainties due to vagueness. The fuzzy waste load allocation model (FWLAM) incorporate QUAL2E as a water quality simulation model and Genetic Algorithm (GA) as an optimization tool to find the optimal combination of the fraction removal level to the dischargers and pollution control agency (PCA). Penalty functions are employed to control the violations in the system. The results demonstrate that the goal of PCA to achieve the best water quality and the goal of the dischargers to use the full assimilative capacity of the river have not been satisfied completely and a compromise solution between these goals is provided. This fuzzy optimization model with genetic algorithm has been used for a hypothetical problem. Results demonstrate a very suitable convergence of proposed optimization algorithm to the global optima.

In this study a Ethanol Amine (EA) production plant was simulated and optimized. Due to the lack of accurate reaction rate information, the first step was obtaining reliable kinetic data from the SRI (Standford research institute) International industrial database and calculation using the error minimization method. By implementing the resulted reaction kinetics then the whole plant was simulated using Hysys software. The simulation results were compared with the SRI data and concluded that there is acceptable agreement between the simulation and the measured industrial data. Finally using the Gradient Search (GS) optimization technique the plant was optimized using the followings as optimization variables: input ammonia to Ethylene Oxide (EO) molar ratio, input water flow rate, and reactor temperature. Employing process profit as the objective function the optimal operating conditions were found to be: ammonia to EO ratio of 5 (mol/mol), water flow rate of 52.59 kg mol/hr, and reactor temperature of 85°C.

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.