Investigating Effects of Vertical Baffles on Damping of Shallow Water Sloshing using a 3D Model

Liquid sloshing is a common phenomenon in the transporting of liquid tanks. A safe liquid transporting needs to control the entered fluctuating forces to the tank walls, before leading these forces to large forces and momentums. Using predesigned baffles is a simple method for solving this problem. Smoothed Particle Hydrodynamics is a Lagrangian method that has been widely used to model such phenomena. In the present study, a three-dimensional incompressible SPH model has been developed for simulating the liquid sloshing phenomenon. This model has been improved using the kernel gradient correction tensors, particle shifting algorithms, turbulence model, and free surface particle detectors. The results of the three-dimensional numerical model are compared with an experimental model, showing a very good accuracy of the three-dimensional numerical method used. This study aims to investigate vertical baffle effects on the control and damping of liquid sloshing. The results of the present investigation show that in this particular case, by using baffles, it is possible to reduce more than 50% of the maximum value of pressure fluctuations in the slashing phenomenon

Isothermal gasification kinetics of char from municipal solid waste ingredients using the thermo-gravimetric analysis

The study focused on exploring the kinetic parameters of wastes in gasification experiments with CO2. The feedstock of mixtures was pyrolyzed using the thermo-gravimetric analyzer at different temperatures under an inert environment. The proximate analysis of the sawdust and Polyethylene revealed that biomass contains carbon and oxygen in almost equal amounts, therefore highlighting the problem of high oxygen content in its bio-oil. Polyethylene evidently has no oxygen content, making it an ideal co-feedstock for pyrolysis by TGA. On the other hand, Polyethylene contains all its organic matter in volatile form and does not contribute to forming char. The pyrolysis behavior was assessed by estimating the kinetic parameters, using the isothermal models of Zero-order (R2 = 0.978), Contracting area (R2 = 0.962), and Avrami-Erofeev (R2 = 0.960), Power Law (R2 = 0.960), indicating the most suitable models for CO2 gasification-pyrolysis. In conclusion, the low activation energy of wastes degradation using the model-free method (8.079 × 107 J kmol−1) in the low range of the wood waste activation energy, indicating the suitability of both materials for co-pyrolysis because of the synergistic effects between biomass and plastics, uniformity between materials, and also the high surface area of the mixture (101 m2 g−1). Finally, the TGA model is used to assess the kinetic parameters of these chars by gasification method

Statistical analysis of the effective factors on the 28 days compressive strength and setting time of the concrete

In this study, the effects of various factors (weight fraction of the SiO2, Al2O3, Fe2O3, Na2O, K2O, CaO, MgO, Cl, SO3, and the Blaine of the cement particles) on the concrete compressive strength and also initial setting time have been investigated. Compressive strength and setting time tests have been carried out based on DIN standards in this study. Interactions of these factors have been obtained by the use of analysis of variance and regression equations of these factors have been obtained to predict the concrete compressive strength and initial setting time. Also, simple and applicable formulas with less than 6% absolute mean error have been developed using the genetic algorithm to predict these parameters. Finally, the effect of each factor has been investigated when other factors are in their low or high level