Structural design analyses of industrial dye mixing machines, concerning mixing impeller geometries, mixing performances, and power requirements aren't generally of scientific quality. Our aim is to propose a practical method for minimizing execution time, using parametric design. In this study, Visual Basic API codes are developed in order to model the impellers in SolidWorks software, and then flow analyses are conducted. Thus, velocity values and moment/torque values required for mixing operation are determined. This study is carried out for different shaft rotational speeds and different impeller diameters. Flow trajectories are obtained. After that, frequency analyses are conducted and natural frequency values are obtained. In the scope of this study, two different impeller types are investigated.

This work examines the reduced-cost design optimization of dual- and multi-band antennas. The primary challenge is independent yet simultaneous control of the antenna responses at two or more frequency bands. In order to handle this task, a feature-based optimization approach is adopted where the design objectives are formulated on the basis of the coordinates of so-called characteristic points (or response features) of the antenna response. Due to only slightly nonlinear dependence of the feature points on antenna geometry parameters, optimization can be attained at a low computational cost. Our approach is demonstrated using two antenna structures with the optimum designs obtained in just a few dozen of EM simulations of the respective structure.

A new Computer-Aided Design approach is introduced for design of steel castings taking into account the feeding ability in sand moulds.

This approach uses the geometrical modeling by a CAD-program, in which the modul “Castdesigner” is implemented, which includes the

feeding models of steel castings. Furthermore, the feeding ability is guaranteed immediately during the design by an interactive geometry

change of the casting cross section, so that a directional feeding of the solidifying casting from the installed risers is assured.

In the paper, a general topology of continuous-time Active-RC filter is presented. The model includes all possible Active-RC filter

structures as particular cases and allows us to analyze them using a unified algebraic formalism. This makes it suitable for use in computeraided analysis and design of Active-RC filters. By its construction, the model takes into account the finite DC gain and the finite bandwidth as well as non-zero output resistance of operational amplifiers. Filters with ideal OPAMPs can be treated as particular cases. Sensitivity and noise analysis of Active-RC filters is also performed in the proposed general setting. The correctness of the model is verified by comparison with SPICE simulation.

In the paper, a procedure for precise and expedited design optimization of unequal power split patch couplers is proposed. Our methodology aims at identifying the coupler dimensions that correspond to the circuit operating at the requested frequency and featuring a required power split. At the same time, the design process is supposed to be computationally efficient. The proposed methodology involves two types of auxiliary models (surrogates): an inverse one, constructed from a set of reference designs optimized for particular power split values, and a forward one which represents the circuit S-parameter gradients as a function of the power split ratio. The inverse model directly yields the values of geometry parameters of the coupler for any required power split, whereas the forward model is used for a post-scaling correction of the circuit characteristics. For the sake of illustration, a 10-GHz circular sector patch coupler is considered. The power split ratio of the structure is re-designed within a wide range of ��6 dB to 0 dB. As demonstrated, precise scaling (with the power split error smaller than 0.02 dB and the operating frequency error not exceeding 0.05 GHz) can be achieved at the cost of less than three full-wave EM simulations of the coupler. Numerical results are validated experimentally.