Search for tag: "heat"

12g 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 0 likes 216 plays 0  

10c Closed system examples

Here I go through two examples of the first law of thermodynamics for closed systems. The first on e is a polutropic process where I calculte the final conditions and the heat and work. The second…

From  Stephen Beck 0 likes 756 plays 0  

13a Heat engines

Here I introduce the concept of the heat engine. I define the source and the sink. I then use the first and second laws of thermodynamics to derive the Carnot efficiency. I then point out that the…

From  Stephen Beck 0 likes 662 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 0 likes 569 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 0 likes 614 plays 0  

14c Brayton cycle with inefficiencies

Here I introduce two ineffinciencies into the ideal Brayton cycle I described in the previous lecture. Firstly, the effect of friction on the turbine and compressore. Then, I look at the effect of…

From  Stephen Beck 0 likes 687 plays 0  

14b Example of Brayton cycle

Here I go through an example of a Brayton cycle. I show that, using previous knowledge of devices, we can calculte the heat and work terms for the three devices and therefore work out the efficiency…

From  Stephen Beck 0 likes 711 plays 0  

13b Power cycles and diagrams

Here I show that the area under the PV and TS diagrams are the work produced in a cycle. I show (again that the efficiency is the ratio between work out and heat in, but here I do it graphcally.

From  Stephen Beck 0 likes 578 plays 0  

10e Open system examples

Here I go through 2 examples of use of the SFEE for ideal gases. The fiart on is a turbine and the second one is an isothermal compressor. I show how to solve tese and what they mean.

From  Stephen Beck 0 likes 681 plays 0  

12f 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 0 likes 273 plays 0  

9c Specific Heat Capacities

Here I introduce isothermal processes. I then derive the specific heat capacities at constant volume and pressure. I reinforce that these can always be used to substiture for temperature. Finally I…

From  Stephen Beck 0 likes 958 plays 0  

10b Polytropic processes

Here I show that the polytropic process is a good way of describing changes in condition for closed systems with ideal gasses. I look at different values of the exponent, n. Then I calculate some at…

From  Stephen Beck 0 likes 1,069 plays 0  

9a The energy equation

Here I introduce the first law of thermodynamics by thinking about the types of energy that we will deal with. I then shpow that these are interchangeable. Finally, I deduce the energy equation.

From  Stephen Beck 0 likes 1,069 plays 0  

The Solar System

Paul Crowther provides an overview of the planets, asteroids and comets within our Solar System, plus a sense of its scale, enhanced by stunning images from astronauts, NASA, and ESA spacecraft.

From  Tom Foster 0 likes 121 plays 0