Multiphase flows have been a significant problem in the oil and gas industry, with many recent reports of failures in industrial piping and equipment due to erosion either from long-term liquid impingements or solid particles. One of the most efficient horizontal sand separators is the product developed by Specialized Desanders Inc., which is called the “Horizontal Desander.” It is a gravity-based separator, and the associated multiphase flow physics has been investigated in this research. This study analyzes the phase separation by applying multiphase numerical analysis using Star CCM+ software. Experimental testing with the two-phase flow (air and water), and three-phase flow (air, water, and sand) were performed and compared to the numerical results. After confidence is established in the numerical model, a four-phase simulation was performed to analyze the sand distribution at different operating pressures. The Particle Image Velocimetry measurements applied to the two-phase experiment showed that the time-averaged, RMS of velocity fluctuations and the frequency analysis of the air-liquid interface are in an acceptable agreement with the simulation results. Both the experiment and the simulation results have shown that 99% of sand has settled within 54% of the Desander length. The four-phase simulations show that higher operating pressures reduce the liquid level, and this affects the velocity of phases inside the Desander. The velocity changes result in changes to the tr

parabola-shaped trajectories, because gravity affects the body's vertical motion and not its horizontal. At the peak of the projectile's trajectory, its vertical Newton's laws of motion are three physical laws that describe the relationship between the motion of an object and the forces acting on it. These laws, which provide the basis for Newtonian mechanics, can be paraphrased as follows: A body remains at rest, or in motion at a constant speed in a straight line, unless it is acted upon by a force. At any instant of time, the net force on a body is equ If the body is not released from rest but instead launched upwards and/or horizontally with nonzero velocity, then free fall becomes projectile motion. When air resistance can be neglected, projectiles follow parabola-shaped trajectories, because gravity affects the body's vertical motion and not its horizontal. At the peak of the projectile's trajectory, its vertical velocity is zero, but its acceleration is g {\displaystyle g} downwards, as it is at all times. Setting the wrong vector equal to zero is a common confusion among physics students.