Oil liquid sloshing is a common phenomenon in automobile fuel tank under variable working conditions. Installing baffles in automobile fuel tank is the most effective way to suppress adverse influence caused by oil liquid sloshing. Different types of three-dimensional finite element models filling oil liquid are created, meshed, and simulated. The reliability of simulation results is verified by test. The concept of time–area value is proposed in this work. In order to explore the influence of different baffle factors on oil liquid sloshing, six factors are studied. Six kinds of influencing factors are height, structure, shape, spacing, number, and placement of baffles. The sloshing pressure and time–area value are the core parameters for evaluating the influence degree. Some results could be obtained by comparing the parameters of oil liquid sloshing under the same condition. High baffles and baffles with small spacing have obvious attenuation influence on the pressure of oil liquid sloshing. Low baffles, double baffles, parallel baffles, and the combined action of inertia force and gravity are more beneficial to the reduction of time–area value. Time–area value is the largest and the smallest in fuel tank with intersection baffles and low baffles, respectively.

Oil liquid sloshing is the sloshing of free oil liquid surface in the fuel tank filled partially. The variable conditions of vehicle mainly include braking, acceleration, and deceleration. It is verified that the simulation method is reliable by the test. In this study, numerical simulations are carried out to study the sloshing of free oil liquid surface under the variable conditions of vehicle, and the key factors influencing variable conditions are acceleration value of oil liquid sloshing, the lasted time of acceleration, and the amount of fuel filled. The numerical results of oil liquid sloshing under variable conditions are compared. The results show that the influence of the amount of fuel filled on oil liquid sloshing and evaporative emission is greater than that of the other two factors under the same working conditions. The time-area values of acceleration lasted time of 1 s are bigger than that of 4 s and the time-area values of 50% fuel filled are bigger than that of 25% fuel filled during the same time of sloshing, and the change law of evaporative emission is the same as that of time-area values.

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.

The shape of fuel tank is one of the main factors influencing oil liquid sloshing in fuel tank without baffles. The change of oil liquid sloshing pressure and free oil liquid surface area in fuel tanks of different shapes is the focus of this study. First, the reliability of the simulation method is verified by the test. Second, three different shapes of fuel tanks, which are rectangle, ellipse, and triangle, are proposed, and each shape of fuel tank is improved. A series of simulations are carried out under the same condition. The related history curves of oil liquid sloshing pressure and free oil liquid surface area are obtained, and the pressure contours of oil liquid sloshing and position diagrams of free oil liquid surface are displayed in the process of oil liquid sloshing. Finally, simulation data are compared and analyzed. In three different shapes of fuel tanks, it is found that the pressure of oil liquid sloshing in elliptical fuel tank is the biggest and time-area value of free oil liquid surface area in triangular fuel tank is the smallest. The curved bottom wall of fuel tank is beneficial to reduce the pressure amplitude of oil liquid sloshing and time-area value. All things considered, the heart-shaped fuel tank is optimal for reducing the pressure amplitude of oil liquid sloshing and evaporative emission under the same condition.

In order to investigate the effects of different shapes of hydrogen inlet ports on the behavioral characteristics of hydrogen in Type IV hydrogen storage cylinders under rapid refueling conditions, a mathematical model of hydrogen temperature rise and a three-dimensional numerical analysis model were developed. The rectangular, hexagonal, triangular, Reuleaux triangular, circular, elliptical and conical inlet ports were researched by using computational fluid dynamics methods. The results showed that, for the same refueling flow rate and cross-sectional area, the hydrogen temperature inside a cylinder with a rectangular inlet port is higher and the jet tilt angle is larger than for a hexagonal port, while the thermal stratification phenomenon is not obvious. The hydrogen temperature inside a cylinder with a triangular inlet port is lower than that with a Reuleaux triangle port and the jet tilt angle is larger, and neither has significant thermal stratification. The hydrogen temperature inside a cylinder with a circular inlet port is higher than that with an ellipse port, the jets are not tilted on either one, and the phenomenon of thermal stratification is prominent. Further analysis indicated that enlarging the cross-sectional area and increasing the refueling flow rate results in a higher hydrogen temperature and intensified thermal stratification and an upward-angled jet can effectively reduce or eliminate thermal stratification.