Pitot tubes are small, right angle shaped tubes that can measure the velocity of a fluid. They are an important part of an airplane, where they are used to provide the pilot with in-flight velocity measurements. When the fluid enters the pitot tube, it is forced to come to a stop. At some point in […]
Bernoulli Equation Examples
October 11, 2013 by Leave a Comment
For reference, the Bernoulli equation is: $latex E_t = E_p + E_v + E_z\newline \indent =\frac{p}{\rho}+\frac{v^{2}}{2}+zg\hspace{20px}^{(SI)}\newline \indent =\frac{p}{\rho}+\frac{v^{2}}{2g_c}+\frac{zg}{g_c}\hspace{20px}^{(US)}&s=2$ Example 1 A reservoir contains an outlet that consists of a pipe that discharges water 50 ft below the top of the reservoir. What is the velocity of the water exiting the pipe (at point B)? Solution […]
How to Use the Bernoulli Equation
October 10, 2013 by Leave a Comment
The Bernoulli equation states that the total energy possessed by a fluid is the sum of its pressure, kinetic, and potential energies. $latex E_t = E_p + E_v + E_z\newline \indent =\frac{p}{\rho}+\frac{v^{2}}{2}+zg\hspace{20px}^{(SI)}\newline \indent =\frac{p}{\rho}+\frac{v^{2}}{2g_c}+\frac{zg}{g_c}\hspace{20px}^{(US)}&s=2$ Using this starting point, we can calculate the total head, ht, and total pressure, pt, that the fluid is under: $latex […]
How to Calculate Fluid Energy
October 8, 2013 by Leave a Comment
The energy of a fluid comes in the following forms: Kinetic Energy (if it is moving) Potential Energy Pressure Energy Kinetic Energy Since energy is required to accelerate a stationary body, a moving mass of fluid flow possesses more energy than an identical, stationary mass. This energy difference is the kinetic energy of the fluid. […]
How to Calculate Hydraulic Radius
October 7, 2013 by Leave a Comment
Hydraulic radius is used in various engineering applications, particularly in the calculation of pipe and channel flow. It is defined as the flow area divided by the wetted perimeter. $latex r_h = \frac{Flow Area}{Wetted Perimeter}&s=2$ Flow Area This is the cross-sectional flow area of the channel or pipe. When a pipe is flowing under pressure, […]
How to calculate Tailwater
October 3, 2013 by Leave a Comment
Tailwater is defined as the depth of flow in a channel immediately downstream of a drainage facility. Since a drainage structure can create a constriction, the tailwater is usually a starting point, from which the resulting headwater is calculated. Early in my career I was confused by this, because it would seem that building a […]
How to Calculate Runoff
October 1, 2013 by Leave a Comment
Calculating the design flow, or runoff, is usually one of the most difficult parts of an engineering project. We’ve come a long way towards defining some of the abstractions, but unfortunately it is still an inexact science. There are three primary methods to calculating a design flow (and one additional important consideration): Rational Method SCS […]
The Work Energy Principle Explained
September 30, 2013 by Leave a Comment
Since energy can be neither created nor destroyed, external work performed on a system changes the system’s total energy. $latex W = {\Delta}E = E_2 – E_1$ The work energy principle introduces some simplifications into many mechanical problems, such as: You don’t need to know the acceleration of a body to calculate the work performed […]
All About Asphalt Aggregates
September 25, 2013 by Leave a Comment
Aggregates comprise about 90 – 95% by weight and 75 – 85% by volume of the average asphalt mix. The properties of the final asphalt product are greatly affected by the grading of the aggregate. Coarse Aggregate is material retained on the #8 sieve (2.36 mm and larger). Fine Aggregate is material passing through the […]
What are the types of Portland Cement?
September 24, 2013 by Leave a Comment
Portland cement is the primary ingredient in concrete. It is produced by burning a mixture of lime and clay in a rotary kiln and grinding the resulting mass. ASTM C-150 describes 5 classifications of portland cement Type 1: Normal portland cement Type 2: Modified portland cement Type 3: High-early strength portland cement Type 4: Low-heat […]