BOURDAN PRESSURE GAUGE and types of fluid flow.pptx

bourdan pressure gauge

1. Bourdon tube pressure gauges The Bourdon gauge consists of a tube bent into a coil or an arc. As the pressure in the tube increases, the coil unwinds. A pointer connected to the end of the tube can be attached to a lever and a pointer calibrated to indicate pressure . The Bourdon tube pressure gauge works by estimating the amount of change in a coiled or semicircular metal tube by a pressurized fluid-filled inside. This is because of the principle that a flattened tube will in general regain its circular structure when pressurized . With a C-shaped tube,  when the pressure inside the tube increases the closed end of the C opens out, thus the displacement of the closed end becomes a measure of the pressure. A C-shaped Bourdon tube can be used to rotate, via gearing, a shaft and cause a pointer to move across a scale.

2. Bourdon tube pressure gauges The Bourdon-tube gauge, invented about 1850, is still one of the most widely used instruments for measuring the pressure of liquids and gases of all kinds, including steam, water, and air up to pressures of 100,000 pounds per square inch (70,000 newtons per square cm ). A bourdon tube is the most commonly used pressure gauge. It is a mechanical instrument that measures the pressure without an electric supply. It is made of steel to resist wear and corrosion. A bourdon tube pressure gauge can measure pressure from 0.6 to 7000 bar (8 to 10000 psi). It is compatible with liquid or gaseous media for vacuum, as well as low and high-pressure applications. It is a compact instrument that is ideal for heavy vibration application and dynamic pressure load. The bourdon tube pressure gauge is as shown below.

3. UNIT-2 FLUID KINEMATIC AND FLUID DYNAMICS Fluid Kinematics:Kinematics of flow is an essential aspect of fluid mechanics that deals with the study of the motion of fluid particles without considering the force acting on them. It focuses on describing the movement of fluid elements, such as velocity, acceleration, and displacement, as they travel through a fluid medium. Fluid statics is the part of fluid mechanics that deals with fluids when there is no relative motion between the fluid particles . F luid dynamics is a subdiscipline of fluid mechanics that describes the flow of fluids — liquids and gases. It has several subdisciplines , including aerodynamics (the study of air and other gases in motion) and hydrodynamics (the study of liquids in motion).

4. TYPES OF FLUID FLOW Laminar Flow Laminar flow is a smooth and orderly type of fluid flow characterized by parallel layers of fluid particles moving without significant mixing. In laminar flow, the particles move in a predictable manner, following well-defined streamlines. It occurs at low velocities, high viscosities, and in the absence of obstructions, creating an organized and predictable flow pattern . Turbulent Flow Turbulent Flow is a dynamic and chaotic type of fluid flow characterized by irregular motion and the formation of eddies, vortices, and fluctuations in velocity and pressure. It occurs at high velocities, low viscosity, and in the presence of disturbances or obstacles, playing a significant role in many natural and engineered systems.

5. TYPES OF FLUID FLOW Steady Flow Steady flow refers to a condition in fluid dynamics where the properties of the flowing fluid, such as velocity, pressure, and temperature, remain constant at any given point within the flow field over time. It implies a consistent and unchanging flow rate, allowing for simplified analysis and prediction of fluid behavior in a wide range of engineering and scientific applications. Unsteady Flow Unsteady flow, also known as transient flow, refers to fluid motion where the properties, such as velocity, pressure, and temperature, vary with time at different points in the flow field. It occurs during start-up or shutdown processes, sudden changes in flow conditions, or any situation where fluid properties change dynamically, highlighting the time-dependent nature of the flow behavior .

6. TYPES OF FLUID FLOW Compressible Flow Compressible Flow refers to the movement of fluids, typically gases, where changes in density and pressure significantly impact the flow behavior . In compressible flow, the fluid’s compressibility plays a vital role, resulting in variations in density, velocity, and pressure throughout the flow field. Understanding compressible flow is crucial in fields such as aerodynamics, rocket propulsion, and gas dynamics. Incompressible Flow Incompressible Flow refers to the behavior of fluids, typically liquids, where the density remains constant regardless of changes in pressure. This type of flow is commonly assumed in low-speed and low-pressure systems, where the volume of the fluid remains constant, allowing for simplified analysis and calculations of fluid behavior and flow patterns.

7. TYPES OF FLUID FLOW Rotational Flow: A flow is rotational if fluid elements undergo rotation about their axis while flowing along streamlines. The flow is rotational when its vorticity vector is non-zero in some of its regions . Irrotational flow: Irrotational flow is a flow in which no element of the moving fluid rotates in any direction from one instant to the next. Therefore, only a torque applied by shear forces on the sides of a fluid particle can cause it to rotate.

8. CONTINUITY EQUATION RATE OF FLOW (Q): The motion of fluids is assessed by studying their flow rate, which is the volume of fluid passing a cross-section each second. The flow rate formula is the velocity of the fluid multiplied by the area of the cross-section: Q = v × A . The unit for the v olumetric flow rate Q is m 3 / s . Continuity equation represents that the product of cross-sectional area of the pipe and the fluid speed at any point along the pipe is always constant. This product is equal to the volume flow per second or simply the flow rate. The continuity equation is given as: R = A v = constant.

9. CONTINUITY EQUATION

10. CONTINUITY EQUATION The equation based on the principle of conservation of mass is called Continuity equation. Thus for a fluid flowing through the pipe at all cross- sections, the quantity of fluid per second is constant. Consider two cross- sections of a pipe . Let V1 = Average velocity at cross- section 1-1 ρ1 = Density of fluid at section 1-1 A1 = Area of pipe at section 1-1 And V2, ρ2, A2 are the corresponding values at section 2-2 Then the rate flow at section 1-1 = ρ1A1V1 Rate of flow at section 2-2 = ρ2 A2V2 According to law of conservation of mass Rate of flow at section 1-1= Rate of flow at section 2-2 ρ1 A1 V1 = ρ2 A2 V2 This equation is applicable to the compressible as well as incompressible fluids and is called “Continuity equation”. If the fluid is incompressible, then ρ1 = ρ2 and the continuity equation reduces to A1 V1 = A2 V2