Introduction

Modern society and living conditions are made possible by advances in science, technology, engineering and mathematics (STEM). The subjects studied in these fields have become so relevant that any person not familiar with their basic principles is at a disadvantage. Consequently, the study of STEM fields must be encouraged throughout academic education. Even then, no one should stop there. Real things are dynamic, always changing, so one must engage in lifelong learning. In fact, this is a personal motivation to start this blog.

So what lies ahead?

During many years in higher education, I have learned that complex problems can be solved by breaking them down into simpler problems. In STEM fields, this means analyzing the problems from the fundamental concepts. In other cases, students might also need a reference in topics that are of great importance. As a result, the entries in this blog will present these concepts with thorough explanations that can help any student at different academic levels.

Statement of Purpose

Provide students of all ages and levels with articles and information that can help them understand a variety of concepts of STEM fields. I will do my best to organize and label entries with key words, so anyone can easily find what they look for.

Anyone reading the blog is welcomed to comment, make suggestions and point out errors. I hope this becomes helpful to many around the world.

Enjoy!

Stoichiometry in Combustion (Part 2 - Example with Excess Air)

Determine the air-fuel ratio on a mass basis for the complete combustion of octane, C8H18, with 150% theoretical air (50% excess air).

Solution:

The first part of the solution is to obtain the equation for the complete combustion of octane with the theoretical amount of air. Find the coefficients of the equation.

The second part of the solution is using the left hand side of the chemical equation to obtain the new coefficients of the products when 150% theoretical air is used. Now, the air is multiplied by 1.5, and there is excess air that appears as uncombined oxygen in the products.

The third part of the solution is actually calculating the air-fuel ratio which is what the problem asked for.

The ratio of the amount of air in this reaction to the amount of fuel is about 22.7.

Bibliography:

Michael J. Moran, Howard N. Shapiro. Fundamentals of Engineering Thermodynamics. John Wiley & Sons, Inc., 2008.