02 Statika Fluida Part4 MEKFLU

Introduction

This tutorial covers fundamental concepts of fluid statics, including pressure at a point, Pascal's law, atmospheric pressure, and hydrostatic forces. Understanding these principles is essential for engineering applications involving fluids, such as hydraulics and buoyancy.

Step 1: Understanding Pressure at a Point

• Pressure is defined as force per unit area.

Use the formula

[ P = \frac{F}{A} ] where P is pressure, F is the force applied, and A is the area over which the force is distributed.
• Remember that pressure is exerted uniformly in all directions in a fluid at rest.

Step 2: Applying Pascal's Law

• Pascal's law states that any change in pressure applied to an enclosed fluid is transmitted undiminished throughout the fluid.
• Practical application: This principle is used in hydraulic systems, where a small force can be amplified to lift heavy objects.

Step 3: Exploring Variations in Pressure

• Atmospheric pressure is the weight of the air above a surface and varies with altitude.
• Standard atmospheric pressure at sea level is approximately 101.3 kPa (kilopascals).
• As you go higher, atmospheric pressure decreases, affecting fluid behavior and measurements.

Step 4: Using Manometers for Pressure Measurement

• A manometer is a device used to measure the pressure of a fluid.
• Types of manometers include open and closed types.

To read a manometer

• Note the height difference between the fluid levels in the two arms of the manometer.

Use the formula to calculate pressure difference

[ P = \rho g h ] where (\rho) is the fluid density, g is the acceleration due to gravity, and h is the height difference.

Step 5: Calculating Hydrostatic Force on Surfaces

The hydrostatic force acting on a surface can be calculated using

[ F = \rho g A h_{c} ]

where

• F is the hydrostatic force,
• (\rho) is the fluid density,
• g is the acceleration due to gravity,
• A is the area of the surface,
• (h_{c}) is the depth of the centroid of the surface below the fluid surface.
• Consider both flat surfaces and curved surfaces when applying this formula.

Step 6: Understanding Buoyancy and Archimedes’ Principle

• Archimedes’ principle states that a body submerged in a fluid experiences a buoyant force equal to the weight of the fluid displaced.

To calculate buoyant force

[ F_{b} = \rho_{f} V_{d} g ]

where

• (F_{b}) is the buoyant force,
• (\rho_{f}) is the fluid density,
• (V_{d}) is the volume of fluid displaced,
• g is the acceleration due to gravity.
• Use this principle to analyze stability in floating bodies.

Step 7: Analyzing Pressure Variations in Moving Fluids

In moving fluids, pressure can vary based on velocity changes, following Bernoulli's equation

[ P + \frac{1}{2} \rho v^{2} + \rho gh = constant ]

where

• P is the pressure,
• (\rho) is the fluid density,
• v is the fluid velocity,
• h is the height above a reference point.
• Recognize that increases in fluid velocity can lead to decreases in pressure.

Conclusion

Understanding the principles of fluid statics, including pressure measurement, hydrostatic forces, buoyancy, and fluid dynamics, is crucial for engineering applications. Familiarity with these concepts will enhance your ability to analyze and design systems involving fluids. For further learning, consider exploring advanced topics in fluid mechanics or practical applications in hydraulic systems.