One of structural passive control methods is to use Tuned Liquid Damper (TLD). However, because of the nature of the TLD, only one tuning frequency can be created when the water is sloshing. To fix this problem, some installed ROTATABLE BAFFLES can be embedded inside TLD called Variably Baffled TLD (VBTLD) where by changing the angle of the BAFFLES a tuning frequency range is created. This gives the passive control system the capability to be pre-tuned according to the desired frequency. In this paper, the effects of rectangular and cylindrical shapes of container on behavior of VBTLD are studied and numerically validated with experimental results. There are four BAFFLES inside each damper tuned manually in different cases. In numerical investigation, the rectangular TLD created greater returning force than cylindrical TLD in all depth and angle selections. By increasing the baffle angle, from 0 ° to 80 ° at the water depths of 4, 5. 2 and 6. 4 cm, the control forces are increased 59. 8%, 38. 4% and 30. 2% respectively for rectangular TLD and 58. 4%, 50. 4% and 46. 1% for cylindrical TLD.

Structural control is considered as an efficient method to improve seismic behavior of buildings. Control methods are divided into passive, active, hybrid and semi-active due to adaptability and need to external energy. Semi-active control methods have the reliability of passive systems, and at the same time maintain the consistency and variability of active systems. In this method, structural responses decrease based on the change in damping properties or stiffness of the system. Tuned Liquid Damper, TLD, has a dual operation: it can be used as a damper and water tank. It has low manufacturing, installation and maintenance costs. In this damper, water sloshing reduces the vibration of the structure. In the recent years, researchers have tried to use the BAFFLES and perforated plates in the damper tank to increase the energy dissipation

In this study, to improve the efficiency of TLD, a Variably Baffled Tuned Liquid Damper (VBTLD) was used. The BAFFLES are so that they divide the tank into three equal parts when they are fully closed. Furthermore, when they are open or partially closed, they can serve as some obstacles and improve the energy dissipation parameters. When this damper meets an excitation with a specific frequency, the BAFFLES can be tuned to make the frequency of sloshing equal to that frequency. VBTLD used in this paper could be set for frequency range from 1. 73 to 3 times of a specific frequency. Compared to a simple TLD, VBTLD can be tuned to a range of frequencies and improve the performance of structure against external excitation. At first, the benchmark building was modeled in OpenSees, then the performance of the device was verified by previous test results. To examine performance of VBTLD, Tuned Mass Damper (TMD) with optimal parameters was used in this study. Results show that when the BAFFLES are at the best angle, VBTLD with water depths of 42 mm has maximum response reduction for the numerical model subjected to the Kobe earthquake at intensities of 2, 4, 6 and 8% of the Initial maximum acceleration of the earthquake (PGA=0. 87g). The improvement of structural behavior compared to the optimal mass damper at maximum acceleration are respectively 23. 1, 22, 14. 6 and 10. 5% while for damper with water depths of 63 mm, they are respectively 8. 2, 9. 5, 6. 7 and 6. 8%.

Changing the structure of the microchannel or setting obstacles in the microchannel has become an effective way to improve the mixing performance of a passive micromixer. Here, we design a three-dimensional micromixer with fractal obstacles based on Cantor fractal principle. The effect of fractal obstacle level, micromixer height, spacing between fractal obstacles, and different Re (Reynold number) on the mixing efficiency is studied. Some valuable conclusions are obtained. The micromixer with quadratic fractal obstacles has better mixing efficiency than the micromixer with primary fractal obstacles. With the increase of the micromixer height, the effective folding area of the fluid can be increased. When the spacing between the fractal barriers is 0 μ, m, the mixing efficiency of the micromixer is better. The mixing efficiency of all micromixers can reach more than 90% at Re is less 0. 1 or more than 40. When Re is 70 and 100, the fluid convection in the micromixer is very strong. Finally, the best micromixer CSM600(Cantor structure micromixer with height 600μ, m) is obtained. The mixing effect is superior to other micromixers under any conditions.

In the present study, central composite algorithm was used in order to model and optimize the mechanical behavior of “glass fiber reinforced epoxy composite - structural steel “connections. Initial tests showed that the polymer curing variables play a significant role as key process parameters in producing strong and reliable connections. After conducting Thermal Gravimetric Analysis on polymer, by selecting curing time and curing temperature as input variables, the parameters were coded and each of them was studied in five levels. In order to estimate the desirable response and provide appropriate models, thirteen tests were conducted systematically. In order to assess the accuracy and to validate the proposed model, analysis of variance was performed successfully. The effect of curing time and curing temperature on the connection’s strength quality was studied utilizing two-dimensional graphs. Utilizing this approach the optimal bonding process variables was achieved at 40°C and 180 min for curing temperature and curing time respectively. Finally, the results obtained from micro structural characterization and fractography analyses of joints by Optical and Scanning Electron Microscope were in good agreement with the results achieved by the developed model.

Channel flow with BAFFLES is a multifaceted phenomenon with wide-ranging applications. It plays a crucial role in enhancing mixing, heat transfer, and other fluid dynamics processes. The BAFFLES' design and placement within the channel are crucial to achieving the desired heat transfer enhancement. Based on the specific application and fluid properties, such as baffle geometry, spacing, and orientation must be considered. This work aims to visualize, evaluate, and understand the effectiveness of BAFFLES on heat transfer rates under various operating conditions and design parameters.  Computational Fluid Dynamic (CFD) investigations were carried out to examine the performance of channels for various geometrical configurations including Broken V-shaped, Circular, and triangular at wide operating conditions, and baffle number densities. Computational fluid dynamic (CFD) simulations were carried out for three different baffle shapes while the Reynolds number (Re) ranged from 1800 to 22000 and the no. of baffle sets(N), varied as N=15,20,30. At low Re conditions channel with 30 sets of Broken-V-shape BAFFLES results in a higher Nusselt number due to effective turbulence enhancement and mixing in the channel. Although the thermal performance of a V-shaped BAFFLES case is relatively good the friction factor is more for this case. Triangular BAFFLES exhibited a lower friction factor. A maximum friction factor of 0.92 is observed for N=30 sets at Re= 1800 while the least of 0.76 is recorded for N=15.

Hydraulic structures constructed along the rivers cause disturbances in the natural process of aquatic life and the ecosystem of the region. In order to solve this problem, fishway structure is widely used to facilitate the communication path between downstream and upstream of hydraulic structures crossing the river and to eliminate the inability of fish to swim upstream and also to facilitate their movement downstream of dams. The different types of this structure should be designed to absorb the type of migratory fish in the area and to pass them safely and out of the outlet, without injuring the fish or creating unnecessary delays for the adult spawning fish. Therefore, in the present study, in order to determine the optimal configuration of the T shape BAFFLES used in the path, three types of arrangements were numerically simulated using OpenFOAM software and K-ε turbulence model. These three types of arrangements are consecutive, alternate and also reversed. Then, the results of the numerical model were validated by comparing it with the results of the related laboratory model. The findings indicate that the numerical model is in good agreement with the laboratory results. Among the three configurations, taking into account different factors, the reverse location of T-shaped BAFFLES with 68.3% backwater, 86.2% flow at less than 0.5 m/s, 84.1% turbulent kinetic energy values less than 0.02 square meters per square second and also 61% energy dissipation percentage, had the best performance.

New Page 1 Articulated liquid cargo vehicles transporting inflammablefuels and dangerous chemical products require special consideration when traveling on urban roads or cruising at highway speeds. The road safety and handling of these kinds of vehicles may be adversely affected when negotiating sharp turns or travelling on slippery roads, which may result in either lateral instabilities or complete rollover of these tanker vehicles. Moreover, directional instabilities in these kinds of vehicle may also introduce an excessive yaw swing or may initiate the jack- knifing of the articulated tanker trucks. In order to overcome the instabilities of these tanker vehicles, installation of lateral BAFFLES in the form of separating walls in the tanker were considered. The static roll and yaw plane models of these vehicles including lateral translation of the liquid inside the tank were developed. Using the static roll model, the rollover threshold of the vehicle is analyzed and the effect of these separating walls on the stability of the vehicle is studied. The yaw plane model is then used to predict the transient response and stability of the tanker vehicle under various road maneuvers. The governing differential equations were solved numerically to obtain the simulation results and optimum values of the parameters.

Sloshing is a well-known phenomenon in liquid storage tanks subjected to base or body motions. Up to now the use of multiple vertical BAFFLES for reducing the sloshing effects in tanks subjected to earthquake has not been taken into consideration so much. On the other hand, although some of the existing computer programs are able to model sloshing phenomenon with acceptable accuracy, the full dynamic analysis subjected to random excitations, such as earthquake induced motions, is very time consuming. In this paper a method is presented for reducing the analysis duration based on first, conducting several dynamic analysis cases by using ANSYS-CFX for rectangular tanks of various dimensions, subjected to seismic excitations, and then, using neural network to create simple relationships between the dominant frequency and amplitude of the base excitations and the maximum level of liquid in the tank during the sloshing. The numerical modeling has been verified by using some existing experimental data, and several cases of time history analysis have been conducted to obtain the required numerical results for training a neural network. Finally, the predicted results of the neural network have been compared to those obtained by some other cases of analyses as control values.