Report on Air Flow Rig and Bernoullis
Air Flow Rig – Pitot Static Tube & Venturi Meter
Introduction
In this report I will use a pitot-static tube and a Venturi meter set up within an air flow rig to demonstrate the application of Bernoulli’s Equation and the assumption of inviscid flow. The air flow rig was set up and an imaginary matrix was defined across the cross sectional area of the air flow at the pitot-static section. The matrix had 4 cells going across (A, B, C, and D) the width and 5 cells down the height of the rig (1, 2, 3, 4 and 5). The pitot-static tube will be moved around to the centre of each cell so we can then take a reading for the pressure at that particular point, which can then be used to calculate the velocity across the matrix. This will enable me to determine how the pressure and flow performs in a non ideal situation by comparing the assumed volumetric flow rate at the pitot-static section with the calculated volumetric flow rate at the venturi. This will allow me to further discuss issues relating to why the values are different if they give different results.
Theory
Bernoulli’s equations are based on ideal flows, this means the gases in question obey the equation of state; Pressure x Volume = Constant, and also suggests the flow has zero drag. In most cases flow does have some form of friction, either due to the viscous nature of the fluid or due to the turbulent behaviour of the flow (Sherwin & Horsley, 1996).
The continuity equation is a form of the conservation of mass, applied to flowing fluids. In the flow the mass flow rate of the fluid entering and leaving the system must be the same (Sherwin & Horsley, 1996). It states the product of the density, area and velocity of a fluid is a constant in each particular case: ρ1A1v1=ρ2A2v2 Bernoulli’s energy equation is the conservation of energy applied to fluids and is shown as the following:
P1ρ+v122+z1g=P2ρ+v222+z2g
This shows that the sum of the specific flow energy, the specific kinetic energy and the specific
Introduction
In this report I will use a pitot-static tube and a Venturi meter set up within an air flow rig to demonstrate the application of Bernoulli’s Equation and the assumption of inviscid flow. The air flow rig was set up and an imaginary matrix was defined across the cross sectional area of the air flow at the pitot-static section. The matrix had 4 cells going across (A, B, C, and D) the width and 5 cells down the height of the rig (1, 2, 3, 4 and 5). The pitot-static tube will be moved around to the centre of each cell so we can then take a reading for the pressure at that particular point, which can then be used to calculate the velocity across the matrix. This will enable me to determine how the pressure and flow performs in a non ideal situation by comparing the assumed volumetric flow rate at the pitot-static section with the calculated volumetric flow rate at the venturi. This will allow me to further discuss issues relating to why the values are different if they give different results.
Theory
Bernoulli’s equations are based on ideal flows, this means the gases in question obey the equation of state; Pressure x Volume = Constant, and also suggests the flow has zero drag. In most cases flow does have some form of friction, either due to the viscous nature of the fluid or due to the turbulent behaviour of the flow (Sherwin & Horsley, 1996).
The continuity equation is a form of the conservation of mass, applied to flowing fluids. In the flow the mass flow rate of the fluid entering and leaving the system must be the same (Sherwin & Horsley, 1996). It states the product of the density, area and velocity of a fluid is a constant in each particular case: ρ1A1v1=ρ2A2v2 Bernoulli’s energy equation is the conservation of energy applied to fluids and is shown as the following:
P1ρ+v122+z1g=P2ρ+v222+z2g
This shows that the sum of the specific flow energy, the specific kinetic energy and the specific
References: Bentley, J. P. (2005). Principles of measurement systems. Pearson Education. Granger, R. A. (1995). Fluid Mechanics. Courier Dover Publications. Sherwin, K., & Horsley, M. (1996). Thermofluids. Chapman & Hall. Bibliography URL Links to pages which contained resources which I used: https://wpb1.webproductionsinc.com/danforthfilter/secure/store/Air-Filter-GQ.asp ultra-nspi.com/info_central/glossary/d.php science.nasa.gov/newhome/help/glossary.htm en.wikipedia.org/wiki/Viscosity