The Pulse Detonation Engine is quite a marvel in the field of propulsion. The desirable and impressive part about these engines are:
- Much more efficient than any other kind of engine.
- Their speed may vary form the subsonic to Hypersonic regime, that means quite a great flexibilty for it’s usage.
HOW PDE WORKS?
Following diagram expalins a typical PDE cycle.
Step 1: Air sucked in from Inlet along with this fuel is mixed.
Step 2 : Detonation Process is Initiated.
Step 3: Detonation takes place
Step 4: High pressure gas fills detonation chamber.
Step 5: Detonation “wave” leaves the chamber.
Now “Step 2” is where all the difference lies.
STEP 2 EXPLAINATION==>
PDE engines uses DETONATION and normal engines uses COMBUSTION. Now for common people this two terms are similar but actually there is a lot of difference between them.
COMBUSTION: Combustion technically refers to a process when the subject/fuel is heated in “fixed” amount of air/oxygen. This is not a sudden process and no sudden expansion of volume takes place.
DETONATION: Detonation is said to be take place when the fuel being heated and the process is so fast that there is a sudden expansion of volume that in return produces a “SHOCK WAVE” THAT TRAVELS AT SPEED OF SOUND.
So PDE uses this supersonic waves to push through it’s outlet unlike other engines which pushes hot air through their outlet. Hence due to this simple process PDE has less moving parts than conventional engine.
COUNTRIES WITH PDE RESEARCH ACTIVE?
As of now USA,Russia and India have made their work presented in public domain. All three of the countries are actively exploring the way to harness the millitary potential of this system.
American test prototype aircraft with PDE engine. Though the test only checked the feasiblity of the project and never pushed the a/c to the upper limit. Although there has not been any public appearance from US about this project after 2008, but it is believed that the learnings from this project will be implemented in USA’s Sixth Gen Fighter.
Russian scientists had also successfully tested the first-ever pulse detonation rocket engine on clean fuel in 2016.
DRDO PULSE DETONATED ENGINE RESEARCH
DRDO Oublished it’s studies on Pulse Detonation Engine in 2015, the first public announce of the successful test was made in May 2017. The piblished paper can be found here: http://publications.drdo.gov.in/ojs/index.php/dsj/article/view/8730
A paper released by DRDO mentioned “After achieving single shot detonation in a single tube in liquid fuel, TBRL has achieved multi-cycle operation of 8 Hz in single PDS tube. TBRL is working on air breathing multi-tube multi-cycle pulse detonation engine with an objective to develop an air-breathing Pulse Detonation Engine (with throttling) to generate 2.5 kN of thrust for a duration of 30 minutes.”
Here are the some of the pics of DRDO’s Chandigarh based TBRL Lab PDE Test Bed: