Search for tag: "entropy"

13g Example of throttle and HX

Here I go through the two examples of a throttle and a heat exchanger. I look at the energy equation, and solve that. THen I look at the rate of entropy production. It is positive in both cases…

From  Stephen Beck on January 20th, 2021 0 likes 0 plays 0  

11b Introduction to the second law 2

Here I describe what is hapenning in the two videos of the kid falling off the bike and the kid falling off the bike in reverse. I describe the natural order of things beign that order decreases and…

From  Stephen Beck on January 19th, 2021 0 likes 8 plays 0  

11a Introduction to the second law

Here I show a series of irreversible processes. I discuss how in each case high quality energy is converted into lower quality energy and that this is inevitable. I introduce the concept of entropy.

From  Stephen Beck on January 19th, 2021 0 likes 13 plays 0  

7a Overview of the Thermodynamics course

Here I introduce the course, and inform student how they should be studying. I show the week by week plan . Then I go through the syllabus and pick up some of the fundamental concepts I will be…

From  Stephen Beck on January 18th, 2021 0 likes 174 plays 0  

11b Reversibilities and irreversibilities

Here I show some reversible processes and show that they cannot be really created. This shows the cause of entropy. FRICTION!

From  Stephen Beck on January 4th, 2021 0 likes 15 plays 0  

11a Introduction to the Second law of Thermodynamics

Here I introduce reversibilities and irreversibilities. I show that there is a natural way of things happening.

From  Stephen Beck on January 4th, 2021 0 likes 2 plays 0  

11c Efficiencies and the T-s diagram

Here I introduce the concept of efficiency. I show how these can be shown on a T-s diagram. THis gives the isentropic efficiency.

From  Stephen Beck on January 4th, 2021 0 likes 5 plays 0  

11d Equations for entropy

Here I introduce T-s diagrams and equations for entropy.

From  Stephen Beck on January 4th, 2021 0 likes 5 plays 0  

11d Some equations for entropy

I state that entropy is made out of that due to Irreversibility and that due to heat transfer, Q=TdS. Then I derive the entropy change for solids, liquids and ideal gasses.

From  Stephen Beck on March 16th, 2020 0 likes 156 plays 0  

11c Second law processes and the T-s diagram

Here I introduce the T-s diagram for ideal gasses. I show that an isentropic expansion is a vertical upward line on this and an isentropic compression is a vertical downward line. I then show that in…

From  Stephen Beck on March 16th, 2020 0 likes 224 plays 0  

12e Heat exchangers

I introduce heat exchangers. Then I look at the heat transfer in them from the point of the first law of Thermodynamics. I then explain the irreversibility in a heat exchanger in terms of entropy. I…

From  Stephen Beck on December 11th, 2019 0 likes 194 plays 0  

12e Throttle valves, enthalpy and entropy

We look at the throttle valve,, which is a constant enthalpy device. We see that it reduces pressure and increases the entropy of the flow. THen we compare the throttle to a turbine to get a better…

From  Stephen Beck on January 11th, 2019 0 likes 253 plays 0  

12b Turbines and compressors and the second law

Here we learn about how to deal with both ideal and real turbines and compressors. Work and enthalpy are exchanged. The real case accounts for friction. Compressors require more energy to be put in…

From  Stephen Beck on January 11th, 2019 0 likes 351 plays 0