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Longitudinal liquid sloshing in partially filled clear-bore tanks causes extensive degradation of tankers braking performance. To reduce the negative effect of longitudinal liquid sloshing on tankers, three kinds of transverse baffles were designed, namely, the conventional baffle, the circular baffle, and the staggered baffle. Each kind of baffle...
Citations
... The analyzes of coupled fluid-vehicle systems, in most cases, considered the efforts resulting from a quasi-static loading [8] or used an analog mechanical method [9]. Some have studied the effect of speakers on the overall stability of the tank [10] where a constant deceleration was used to size the baffles. Baffles can be made of composites [11,12] made of natural fibers, which is the next part of this work. ...
... The upper isobar Delta passes through two points: ((Ai -xli) ; 2*rj) and (Ai ; (2*rj -zli)). Where xli and zli are determined by means of the aria S: * /2 S xli zli (9) But the relation: / / xli zli g a (10) That implies: ...
Road safety is extremely important, especially for mobile tanks transporting dangerous fluids. The designer of a portable tanker must calculate the braking forces that could overturn the tanker or destabilize it. The force to be managed during braking results from the pressure of the sloshing fluid applied to the inner walls and to the outer shell of the tank. The shape of the inner walls could improve the stability of the tank. To control the force amplitude, the internal walls can be made of composites. In this paper, determining the forces and pressure value are developed, composite walls are studied in another further work. The objective is to determine the value of the maximum pressure in the tank and to calculate the transverse and vertical forces. The approach is to take the worst moment of the braking as a reference to develop the calculations. The effect of the tank length, the number of internal walls, the filling level, the braking deceleration, and the density of the transported fluid are studied. The results show that the braking force varies from 737 kg to 18,627 tons. If the length value is doubled, the vertical effort is multiplied by a factor of 12,1. If the fluid level is increased by 5% from 93% to 98%, the braking force increase just by, 6,6%. The breaking force increase 10% per 100 kg/m3 of density. For braking deceleration, extreme braking deceleration can increase the fluid pressure by 56,8%. Based on the mobile cistern volume and length, design parameters can be considered by the simplified approach explained in the paper for mobile cisterns design.
... Tere were also 45.16 percent, 25.81 percent, 17.74 percent, and 11.29 percent relative frequencies for each cause. Consequently, rollover and rearend collisions are the two main forms of tanker accidents [8]. Tanker accidents can occur for a variety of reasons, but the most prevalent is liquid sloshing in partially loaded tanks [9]. ...
Ethiopia imports all fuel and crude oils from abroad at high cost, and transportation of these fluids has been carried out by using various capacity of road transportation heavy-duty truck vehicle. Most tanker truck accidents happen during turning because of the fluid splashing in partially loaded tanks and of the uniqueness of the carrying liquids. This is a result of the fact that current baffle configurations are effective at reducing sloshing when braking or accelerating but ineffective at doing so when turning. Consequently, the primary goal of this thesis work is to investigate how different baffle systems affect lateral sloshing reduction. In this work, the optimal baffle configuration and its arrangements for modified oval tanks at 50% and 80% fill levels were tried, and the dynamic analysis of tanker trucks was researched. The tanker truck and baffle system are designed in CATIA V5 for the numerical analysis, and the CFD study is completed in ANSYS Fluent 2021. R2 and the dynamic analysis are carried out in ANSYS LS-DYNA to study the stability of truck. The computational simulation is carried out as a tank with eight types of baffle systems such as existing baffles (TB), TB with BMLB, UMLB, CLB, 2HLB, 2VHLB, 4HLB, and 4VHLB with similar meshing resolution, similar turbulence modeling, similar boundary conditions, and also similar solution strategies. Transverse baffles with bottom-mounted four holes longitudinal baffle with hole-varying position (4VHLB) are discovered to be the best baffle type after evaluating all baffle designs. This suggests that the quantity of sloshing is reduced as the number of holes with small diameters increases. Maximum lateral force and roll moment are reduced by the most, by 47.76% and 58.66%, respectively, at 50% fill level and by 58.08% and 22.52%, at 80% fill level. Consequently, the case tanker truck’s use of this revised design baffle will be crucial for enhancing rollover stability while cornering.
... They studied the relationship between geometrical parameters and the resulting natural frequencies of the liquid. Zheng et al. [7] compared several forms of a conventional, circular, and staggered baffle in a partially filled tank to investigate the size of the holes and the impact angle. Hosseini et al. [8] compared experimental results with several simulation analyses and developed a neural network that showed excellent agreement with new data. ...
This research studies how the angle and dimensions of a single baffle affect the dynamics of a fluid in a closed rectangular tank under an accelerated harmonic vibration in resonance. A half-filled non-deformable rectangular tank with a single centered submerged baffle has been simulated using ANSYS® FLUENT. The study aims to characterize the effect of changing the baffle’s angle; hence, 10 simulations have been performed: without a baffle, 90∘, 30∘, 60∘, 120∘ and 150∘, either maintaining the baffle’s length or the projected height constant. The computational fluid dynamics (CFD) method using volume of fluid (VOF) and large eddy simulation (LES) are used to predict the movement of the fluid in two dimensions, which have been benchmarked against experimental data with excellent agreement. The motion is sinusoidal in the +X direction, with a frequency of oscillation equal to its first vibration mode. The parameters studied have been the free surface elevation, values at three different points and maximum; the center of gravity’s position, velocity, and acceleration; and the forces against the tank’s walls. It has been found that the 90∘ angle has the most significant damping effect, stabilizing the free-surface elevation, reducing the center of gravity dispersion, and leveling the impacting forces. Smaller angles also tame the sloshing and stabilize it.
... Ref. [17] numerically studied the effects of multiple vertical baffles in a rectangular tank by applying harmonic and seismic excitations. Ref. [18] focused on different designs of transverse baffle inside a vehicular tanker to achieve optimal effects based on available Chinese standards. Ref. [19] performed experimental and numerical studies on perforated baffles inside a rectangular tank and studied the damping mechanism of baffles. ...
This article numerically investigates the sloshing dynamics and structural response of baffled cylindrical tanks subjected to lateral resonant as well as seismic excitations. The study focuses on suppressing the sloshing forces and fluid movement by increasing the tank structural strength with the help of a baffle and explores the optimum baffle design from among various ring baffle designs. Two approaches have been used for the evaluation of effective positions and design: the modal approach and the fluid–structure interaction (FSI) approach. The numerical model is validated using the tank design code Eurocode-8. Based on the detailed fluid and structural analysis of sloshing pressure and fluid velocity, the structural stress optimum baffle position and design are achieved, which change the structural characteristics of the tank positively. Furthermore, the effectiveness of the selected design is also tested against the El-Centro and Kocaeli earthquakes. It is found that the optimum design increases the tank structural strength by up to 2.5 and 4 times under resonant and seismic excitations, respectively.
... He did the experiment specifically for sprayer UAV's liquid sloshing and has shown that the inner horizontal and vertical grille can effectively reduce tank liquid sloshing and the oscillation of the sprayer UAV's tank. In the literature, several works have been conducted to reduce big liquid tankers' slosh [80][81][82][83][84]. In Figure 5, the sloshing impact inside a tank has been shown with a 30% filling rate which was experimented by Li Xi [79]. ...
... He did the experiment specifically for sprayer UAV's liquid sloshing and has shown that the inner horizontal and vertical grille can effectively reduce tank liquid sloshing and the oscillation of the sprayer UAV's tank. In the literature, several works have been conducted to reduce big liquid tankers' slosh [80,81,82,83,84]. ...
Over the last decade, Unmanned Aerial Vehicles (UAVs), also known as drones, have been broadly utilized in various agricultural fields, such as crop management, crop monitoring, seed sowing, and pesticide spraying. Nonetheless, autonomy is still a crucial limitation faced by the Internet of Things (IoT) UAV systems, especially when used as sprayer UAVs, where data needs to be captured and preprocessed for robust real-time obstacle detection and collision avoidance. Moreover, because of the objective and operational difference between general UAVs and sprayer UAVs, not every obstacle detection and collision avoidance method will be sufficient for sprayer UAVs. In this regard, this article seeks to review the most relevant developments on all correlated branches of the obstacle avoidance scenarios for agricultural sprayer UAVs, including a UAV sprayer’s structural details. Furthermore, the most relevant open challenges for current UAV sprayer solutions are enumerated, thus paving the way for future researchers to define a roadmap for devising new-generation, affordable autonomous sprayer UAV solutions. Agricultural UAV sprayers require data-intensive algorithms for the processing of the images acquired, and expertise in the field of autonomous flight is usually needed. The present study concludes that UAV sprayers are still facing obstacle detection challenges due to their dynamic operating and loading conditions.
... Gurinder et al. [12] used a CFD process to simulate the motion of the liquid inside an elliptical container with several shapes and arrangements of the barriers. Commercial software such as FLUENT was used to study the influence of the various obstacles on the system dynamics [13,14]. On another hand, experimental studies were performed to evaluate the effectiveness of the barriers with and without circular holes in attenuating the liquid motion inside the containers. ...
The present study deals with the reduction of fluid vibrations by dissipating the kinetic energy in a closed vibrating container partly filled using vertical slotted obstacles. The effect of the barriers on the liquid vibration inside a closed container exposed to a harmonic excitation is numerically studied. A single vertical slotted barrier (SVSB) and multivertical slotted barrier (MVSB) systems are considered for different liquid levels. The 3D liquid domain with the tank and the barrier as boundaries is modelled and solved numerically using ANSYS-CFX software. The reduction in pressures on the walls and the ceiling of the tank due to the influences of the slot size and numbers were evaluated to optimize the size and the numbers of the slots. The numerical approach shows an ability to simulate the nonlinear behavior of the liquid vibration when using vertical slotted barriers (VSB). The obtained results show that the SVSB is more efficient than the MVSB to decrease the dangers of dynamic impacts of the liquid vibrations inside the container. The system-damping factor depends mainly on the slot size and reaches a greatest value at a relative slot size equal to 0.25 for all liquid depth ratios. The presented VSB combines the orifice hydrodynamic action and the integrity of the fluid bulk, which may be relevant for any liquid level. The present model findings agree well with the available analytical and numerical results
... Among them, nonlinearity, linear theory, and simulation analysis of liquid sloshing were deeply studied. 1,2 In many fields, liquid sloshing brings a series of problems, such as driving instability, [3][4][5][6] sloshing noise, 7 structural damage, and evaporative emission. 8 Therefore, the effective control of liquid sloshing is a research direction that scholars pay close attention to at present. ...
Oil liquid sloshing is a normal physical phenomenon in fuel tank under variable conditions of vehicles. Installing baffles in fuel tank is an effective method to suppress oil liquid sloshing. The influence of different baffle shapes on the pressure of oil liquid sloshing and time-area value is the focus of this work. Four factors influencing the baffle shape and baffles of six different shapes are provided in this research. The pressure history curves of oil liquid sloshing at the central point and on the central line, the history curves of velocity of oil liquid mass and volume, oil liquid pressure contours, and the position diagrams of free oil liquid surface were obtained and compared in fuel tanks with baffles of different shapes. Compared with the sloshing pressure of oil liquid and time-area values in fuel tanks with baffles of different shapes, the sloshing pressure of oil liquid at the central point is the smallest in fuel tank with baffles of corrugated shape, and the sloshing pressure of oil liquid on the central line is the smallest in fuel tank with baffles of straight-line shape. However, the baffles of corrugated shape are most beneficial to reduce time-area values.
... An optimum deceleration of 5m/s² [6,14] was applied for time 0 < t < 3 seconds in the longitudinal direction with gravity of 9.81m/s² applied constant throughout. Fluid temperature was 25 °C, fluids densities were 1.225kg/m³ and 998 kg/m³ respectively for air and water, initial fluid velocity as x = 0 m/s, y = 0 m/s, z = 0 m/s at 1 atm pressure inside the chamber was applied. ...
... Fluid temperature was 25 °C, fluids densities were 1.225kg/m³ and 998 kg/m³ respectively for air and water, initial fluid velocity as x = 0 m/s, y = 0 m/s, z = 0 m/s at 1 atm pressure inside the chamber was applied. Time step size used was 0.04s [6] to ensure accuracy. The simulation was carried out till 5 seconds to completely contemplate the effect from the application of brakes to completely coming to a halt. ...
The research is about the effect of a horizontal perforated baffle in suppressing sloshing generated by the application of brakes in tank trucks. Sloshing effect for different fill levels and fluid shifting is measured by means of tracking free surface and center of gravity of fluid via volume of fluid approach
... The effect of the relative liquid movement in the tank on the allowed normal tanker acceleration was examined using the finite element simulation with an attempt to optimise the baffle design in road tankers. The conventional baffle, the circular baffle, and the staggered baffle were considered by Zheng et al. (2013) who used Fluent software to simulate liquid sloshing in tanks equipped with different kinds of transverse baffles and subject to constant braking deceleration. A time-series analysis of the forces act on tank walls and transverse baffles was carried out. ...
... The effect of the relative liquid movement in the tank on the allowed normal tanker acceleration was examined using the finite element simulation with an attempt to optimise the baffle design in road tankers. The conventional baffle, the circular baffle, and the staggered baffle were considered by Zheng et al. (2013) who used Fluent software to simulate liquid sloshing in tanks equipped with different kinds of transverse baffles and subject to constant braking deceleration. A time-series analysis of the forces act on tank walls and transverse baffles was carried out. ...
This paper presents an assessment of the problems encountered with the design, dynamics and stability of road tankers. Generally, the research activities pertaining to these problems may be classified into three groups, liquid sloshing dynamics in moving containers, trucks dynamics carrying solids, and dynamic coupling of liquid-vehicle systems. The modal analysis of liquid free surface for circular, elliptic and generic cross-section geometries is presented together with the corresponding equivalent mechanical models. Considering popularity of horizontal elliptic cross-section tanks, the trammel equivalent pendulum received extensive research activities and the main results are discussed. Design optimisation of the liquid container cross-section and the passive and active control of liquid sloshing approaches are used by engineers to minimise rollover problem. The most difficult problem of road tankers is the coupling dynamics of liquid and vehicle dynamics under different conditions such as braking and lateral acceleration; in this view, computer numerical simulations have been developed.
