Search for tag: "efficiency"

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 on February 4th, 2021 0 likes 150 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 on January 18th, 2021 0 likes 134 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 on January 18th, 2021 0 likes 149 plays 0  

12d Second law examples: Compressor and Nozzle

Here I work through two examples of the effect of isentropic efficiency on devices. I use the nozzle and the compressor as examples. I show that you need to produce a system and a T-S diagram. THen…

From  Stephen Beck on January 14th, 2021 0 likes 164 plays 0  

14a The Brayton cycle

Here I introduce an example of a power cycle. The open cycle Air, Brayton cycle. I look at the three elements and describe what happens in each one. THe I go throught a description of a rea jet…

From  Stephen Beck on January 14th, 2021 0 likes 142 plays 0  

13c The Carnot cycle

Here I introduce an example of the Carnot cycle (open using air). I show that it forms a rectangle on the T-S diagram. I then show that this is the maximum efficiency of a heat engine cycle as: 1)…

From  Stephen Beck on January 13th, 2021 0 likes 130 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 on January 13th, 2021 0 likes 129 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 34 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 391 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 416 plays 0