# Fluid Mechanics Problem: Water Forces on a Parabolic Gate

• Engineering
• ktjj4
In summary, the conversation discusses the application of an external force at point A to keep a gate closed. The force can be directed horizontally, vertically, or at an angle. The exercise at hand only involves cases (i) and (ii), and the question is asking for the components of a force in those cases.

#### ktjj4

Homework Statement
Hello, I'm a little confused for this part of the fluid mechanics problem. I got through calculating the forces of the water on the gate but then it asked me to calculate the horizontal and vertical forces at a certain point (A) on the curved gate to keep equilibrium. I know I have to take the moment about the origin (O) but I am unsure as to why I only have to consider one of the component forces (F_Ax) but not the other (F_Ay). I'm not sure if this is a conceptual thing or if my knowledge of moments is missing something.
Relevant Equations
Sum of M = -Fv(x') + Fh(D-y') - F_Ax(H)

Last edited by a moderator:
ktjj4 said:
I am unsure as to why I only have to consider one of the component forces (F_Ax) but not the other (F_Ay).
The application of an external force at A can keep the gate closed. This force could be directed (i) horizontally, or (ii) purely vertically, or (iii) at an angle. The exercise you are dealing with involves case (i), and case (ii).

NascentOxygen said:
The application of an external force at A can keep the gate closed. This force could be directed (i) horizontally, or (ii) purely vertically, or (iii) at an angle. The exercise you are dealing with involves case (i), and case (ii).
I see, thank you for clarifying that. I assumed the question was asking me to find the components of a force at an angle. Thank You again!

## 1. What is fluid mechanics?

Fluid mechanics is the study of how fluids, such as liquids and gases, behave and interact with their surroundings. It involves the application of principles from physics and mathematics to understand the motion and forces of fluids.

## 2. What is a parabolic gate?

A parabolic gate is a type of hydraulic structure that is shaped like a parabola. It is often used to control the flow of water in a canal or river by raising or lowering the gate to regulate the water level.

## 3. How do you calculate water forces on a parabolic gate?

The water forces on a parabolic gate can be calculated using the principles of fluid mechanics, specifically Bernoulli's equation and the momentum equation. The water level, gate shape, and flow rate are important factors in determining the forces acting on the gate.

## 4. What are the main challenges in designing a parabolic gate?

The main challenges in designing a parabolic gate include determining the appropriate gate shape and size to withstand the expected water forces, ensuring proper operation and control of the gate, and considering the potential impacts on the surrounding environment and structures.

## 5. What are some real-world applications of fluid mechanics and parabolic gates?

Fluid mechanics and parabolic gates have many real-world applications, such as in irrigation systems, hydroelectric power plants, flood control structures, and water treatment facilities. They are also used in the design of ships, airplanes, and other vehicles that move through fluids.