Physics And Bernoulli's Laws

Decent Essays
Introduction

Theoretically, energy in every isolated system will always be conserved so for every action there will be a reaction to stabilise the system (Ellert, G, n.d.). Such a term does also appear in the physics of fluids motion. Fluids are things that can flow such as gas, water or oil. In fluid motion physics there are two theories that are involved with the law of conservation and they are Bernoulli’s law and continuity equation.
Bernoulli’s law is derived from the energy conservation between “kinetic energy and static energy associated with pressure” of an ideal fluid (Encyclopaedia Britannica, n.d.). An ideal fluid is a fluid with a steady flow, incompressible, does not generate heat and has no angular momentum (Brown, S n.d).
W
The Bernoulli’s law suggests that as the pressure will decrease as the velocity increases in a horizontal pipe (PHYS101 Lab Manual, p22, 2017). The continuity equation also suggests similar theory that the velocity of the fluid will increases as the diameter decreases of a pipe according to PHYS101 Lab Manual, p22, 2017. Though, both equations suggestion are very similar, they are however not the same and the aim of this experiment is to verify both equations and their physical limitation.
There are two separated parts in this experiment but they both will be tested out the speed of fluid flow using both equations. First part is an observing and recording of fluid flowing out from a test tube and in second part a Venturi apparatus will be used. In both cases Bernoulli’s equation can be simplified to calculate the velocity of fluid according to experimental conditions.
In the first part of experiment, the pressure is the same for both ends which allow us to remove the pressure and gives: ρgh₁ + ½ρv₁² = ρgh₂ + ½ρv₂²
This can be simplified further by assuming that the velocity at the surface is 0 as it is moving very slowly and the height of the bottom is 0. Using this assumption gives ρgh₁ = ½ρv₂²
Since it is the same fluid so the density, ρ, is the same which they can be cancelled out to give ghsurface = ½

Related Documents

• Decent Essays

In the Carnot cycle all the heat transfer is at constant temperature, and therefore the vapor is superheated in process 3–3. Note, however, that during this process the pressure is dropping, which means that the heat must be transferred to the vapor as it undergoes an expansion process in which work is done. This heat transfer is also very difficult to achieve in practice. Thus, the Rankine cycle is the ideal cycle that can be approximated in practice. In the following sections, we will consider some variations on the Rankine cycle that enable it to approach more closely the efficiency of the Carnot…

• 766 Words
• 4 Pages
Decent Essays
• Decent Essays

5. In the Venturi meter, as the velocity is increased, pressure is decreased, and pressure difference will be utilized to measure the rate of flow. After the pressure difference is generated, the fluid is passed through a pressure recovery exit section. In this section, the 80% of the differential pressure generated at the constricted area, will be recovered. However, in the Orifice plate, all of the pressure loss is not recovered because of friction and turbulence losses in the…

• 1238 Words
• 5 Pages
Decent Essays
• Decent Essays

Abstract In this article, an analytical simulation based on a new model incorporating surface interaction was conducted to study the slip phenomenon in Couette flow at different scales. The velocity profile was calculated by taking account micro-force between molecules and macro-force from the viscous shearing effect, as they contribute to the achievement of slip length. The calculated results were compared with those obtained from the MD simulation, showing an excellent agreement. Further, the effect of the shear rate on slip was investigated. The results can well predict the fluid flow behaviors on a solid substrate, but has to be proved by experiment.…

• 1381 Words
• 6 Pages
Decent Essays
• Decent Essays

Fuel Cells

• 928 Words
• 4 Pages

Furthermore, in the straight pipe, a fully developed laminar assumption is satisfied under the condition that shape change is negligible. Numerical analysis technique the numerical analysis is performed by combining the governing equations related to the conservation of energy, conservation of mass and conservation of electrical charge to examine fluid distributions, heat transfers, mass transfers and electrochemical reactions. The assumptions used in developing the model are as follow: 1) Ideal gas law was employed for gaseous species. 2) The fluid flow in the fuel cell was laminar due to the low flow velocities and the small size of gas flow…

• 928 Words
• 4 Pages
Decent Essays
• Decent Essays

This pressure that is dropped is measured using a pressure sensor that measures the difference in fluid pressure & when calibrated this pressure drop becomes a measure flow rate. The flow rate is given by, Qa = (Cd.A2/√(1-(A2/A1)^2))*(√(2(P1-P2)/P)) Where, Qa = Flow rate Cd = Discharge coefficient A1 = Cross-sectional area of the pipe A2 = Cross-sectional area of the orifice P1, P2 = Static pressures Uses: Orifice plates are most commonly used to measure the flow rates in pipes when the fluid is single-phase (rather than being a mixture of gases & liquids or liquids & solids), the flow rate is continuous instead of pulsating, the fluid occupies the entire pipe (precluding silt or trapped gas), the flow profile is even & well-developed & the fluid & flow rate meet certain other conditions. Small diameter orifice plate is used for gases because gases are compressible & large diameter plate is used for liquid because liquids are incompressible. The concentric orifice plate is used for measuring flow rates of pure fluids. The eccentric as well as segmental orifice plates are used for the measurement of the flow rates of fluids that contains suspended materials like solids, oil mixed with water & wet…

• 917 Words
• 4 Pages
Decent Essays
• Decent Essays

As explained above, the governing equations of the gas mixture that include continuity, momentum and mass fraction of the components, are solved at first. Transient conservation equations are as follow: Mass conservation (1) (∂(ε(1-s)ρ_g))/∂t+∇. (ρ_g u ⃗_g )=S_m In this equation u ⃗_g is superficial velocity vector of gas mixture, which related to intrinsic fluid velocity U as following: (2) (u_g ) ⃗=ε(1-s)U ⃗ In the gas transfer channel, the porosity is equal one and the liquid water volume fraction is zero; so in this area, the superficial velocity will be equal to the intrinsic velocity. Momentum conservation (3) 1/ε(1-s) ∂(ρ_g u ⃗_g )/∂t+1/(ε^2 (1-s)^2 ) ∇. (ρ_g u ⃗_g u ⃗_g )= -∇p_g+1/ε(1-s) ∇.…

• 868 Words
• 4 Pages
Decent Essays
• Decent Essays

The convergent-divergent process is an application of Bernoulli’s principle. (If a fluid flowing through a tube reaches a constriction or narrowing of the tube, the velocity of the fluid flowing through the constriction increases and the pressure decreases. The opposite is true when the fluid leaves the constriction; velocity decreases and pressure increases.) Boyle’s law and Charles’ law also come into play during this process. Boyle’s law: The volume of any dry gas varies inversely with the applied pressure, provided the temperature remains constant.…

• 1872 Words
• 8 Pages
Decent Essays
• Decent Essays

When the spring is stretched, the spring force (Fs) tries to restore the spring to its original position. So the spring force Fs acts opposite to the displacement. We also know that force developed in a liner spring is directly proportional to the deformation (we only consider the case of liner spring). Since the displacement of the spring is opposite to the force Fs, work done by the spring force is negative. So we can write dU= -F_s.dx Integrating from position 1 to 2 ∫_1^2▒dU=-∫_(x_1)^(x_2)▒〖F_s dx〗 We know that for a liner spring Fs = kx.…

• 1828 Words
• 8 Pages
Decent Essays
• Decent Essays

This ideal gas law is essential to the lab as it explains the relationships between the different measurements of a gas and reduces into the combined gas law. The combined gas law is a relation where the number of moles of gas is constant, thus leaving the variables of pressure, volume, and temperature. When comparing the same substance under different conditions, the combined gas law can be mathematically written as (P"1" V"1" )/T"1" = (P"2" V"2" )/T"2" . Since the conditions of the experiment were not at standard temperature and pressure, the combined gas law is required in order to calculate the corresponding volume of hydrogen gas at STP. Single displacement reactions were also…

• 1741 Words
• 7 Pages
Decent Essays
• Decent Essays

Or simply, Ptotal = Pgas1 + Pgas2 + Pgas3 + Pgas4 + ... + Pgas n As previously mentioned, R is the ideal gas constant. In addition to being featured in the Ideal Gas Law equation, R is also used in other equations of thermodynamics. Officially R is equal to 8.314 (L∙kPa)/(mol∙K), 0.08206 (L∙atm)/(mol∙K), or 62.36 (L∙mmHg)/(mol∙K). [1] The objective of the lab is to prove the Ideal Gas Constant in the Ideal Gas Law. The gas, Butane, will be used to drain water from the Procedure A bucket was first filled with water and then the Graduated Cylinder to 250mL.…

• 752 Words
• 4 Pages
Decent Essays