STUDY OF MIXED SAND SEDIMENT AND CHANGES IN FALLING VELOCITY AGAINST MASS, SIZE, AND ROUNDNESS VARIATIONS

• Main Author: STIAWAN (NIM : 20216033), RONI
• Format: Theses
• Language: Indonesia
• Subjects: Fisika
• Online Access: https://digilib.itb.ac.id/gdl/view/30677
• Institution: Institut Teknologi Bandung

The color of sand on the beach has a big influence on tourists' interest. Beaches with bright sand colors like white and golden yellow are preferred by tourists compared to sand with dark colors. This is because sand can affect the appearance of sea water in shallow areas. Brightly colored sand can better light so that the sea water above it looks clearer. To increase the tourist attraction of the beach with dark sand, one effort that can be done is to add a layer of brightly colored sand on it. However, the sand at the bottom of the beach can be disturbed by sea waves and human activities, so that the sand can be lifted and subject to suspension. When experiencing suspension, the grains of sand will move down because of the gravitational force at a certain speed. The speed of this grain depends on several physical factors such as density, diameter, inhibition coefficient and medium viscosity. Various studies have been carried out by scientists to predict the movements of falling grains, but there is no right solution. Velocity equations of falling grain has also been proposed by many researchers, but these equations are very difficult to apply. This study aims to determine how the effect of changes in grain fall velocity on grain mass, size, and roundness variation. Some stages of this research are measuring the time needed for several different types of sand to settle, how the sand sediment layer forms when two types of sand are mixed, and what physical properties affect the speed of falling sand grains. Based on the results that have been obtained, it can be concluded that the mass, size, and roundness of the granules are the most influential factors in the speed of fall.