China's Space Program News Thread

[taxiya]

This is the report of earlier "half system hot test". Probably 2020 or 2019. The difference of latest test from the earlier tests are the full load, the last step to a full engine test.


What are done in these tests:

1. The gas generator is ignited.
2. The ignition procedure is tested.
3. Gas generator runs at a steady load.
4. Turbopump and thrust adjustment device are tested.
5. Temperature and thermal ablation of hot part are checked.

From figure 6, one can see that there is no combustion chamber and nozzle. The white fluid is mixture of atomized water from the fuel pump and air from oxygen pump simulating the pumps work load.

 

[Quickie]

This is the report of earlier "half system hot test". Probably 2020 or 2019. The difference of latest test from the earlier tests are the full load, the last step to a full engine test.
View attachment 69528

What are done in these tests:

1. The gas generator is ignited.
2. The ignition procedure is tested.
3. Gas generator runs at a steady load.
4. Turbopump and thrust adjustment device are tested.
5. Temperature and thermal ablation of hot part are checked.

From figure 6, one can see that there is no combustion chamber and nozzle. The white fluid is mixture of atomized water from the fuel pump and air from oxygen pump simulating the pumps work load.

I think the oxygen turbopump is likely also using water to simulate the LOX being pumped through it. Air does not have the density to simulate the kind of loading stress for a similar propellant flow rate.

 

[gelgoog]

Liquid OXygen has a density of 1.140g/cc i.e. roughly the same as water at 1.0. Kerosene also has a roughly similar density at 0.85g/cc.
So water is a good mass simulator yes. Plus it is a lot easier to handle than either fuel or oxidizer.

 

[taxiya]

I think the oxygen turbopump is likely also using water to simulate the LOX being pumped through it. Air does not have the density to simulate the kind of loading stress for a similar propellant flow rate.

I am also assuming that YF-130 works in the same principle as YF-100. There are two pumps for oxidizer in YF-100, the booster pump and main pump. The main pump seems to be working in gaseous mode.

My understanding is based on this paper where it talked about cavitation. Instead of 汽 (steam), the word is 气 (gas). Strictly speaking, cavitation of liquid fluid (ship propeller) is 汽蚀, while cavitation of gas fluid is 气蚀. So My thought is that oxygen entering the main pump is in gas state rather than liquid.

The author could have been too lazy using 汽 and 气 interchangeably, if so you may be right.

 

[taxiya]

Also need to remember, YF-130 is a oxidizer rich staged combustion. That means all oxygen will enter the gas generator after passing the oxygen main pump. There is no way you can substitute oxygen path with water. Actually my initial thinking of air substituting oxygen was equally wrong too.

 

[Quickie]

Also need to remember, YF-130 is a oxidizer rich staged combustion. That means all oxygen will enter the gas generator after passing the oxygen main pump. There is no way you can substitute oxygen path with water. Actually my initial thinking of air substituting oxygen was equally wrong too.

Actually, there won't be propellant (oxygen/fuel in real operation but water for the test ) piping from the turbopumps to the pre-burner for both the oxidizer-rich and fuel-rich cycle type of engine. The water piping to the turbopumps would have to be separate from the fuel piping going into the pre-burner. The only issue would be that the turbine driving the turbopumps can't be tested to the actual condition where a large volume of the LOX would flow through it in an oxidizer-rich engine.

 

[taxiya]

Actually, there won't be propellant (oxygen/fuel in real operation but water for the test ) piping from the turbopumps to the pre-burner for both the oxidizer-rich and fuel-rich cycle type of engine. The water piping to the turbopumps would have to be separate from the fuel piping going into the pre-burner. The only issue would be that the turbine driving the turbopumps can't be tested to the actual condition where a large volume of the LOX would flow through it in an oxidizer-rich engine.

Are you saying that neither the pre-burner (gas generator) nor the turbine could be tested to the real condition? Especially if the pre-burner is fed with only water? That sounds contradictory to the tests in my post #6763 where it says the gas generator is ignited and the temperature of the gas path was checked within the limit.

I know that the kind of test that you propose does happen, but as I understand it has happened long ago as component test.

 

[Quickie]

Are you saying that neither the pre-burner (gas generator) nor the turbine could be tested to the real condition? Especially if the pre-burner is fed with only water? That sounds contradictory to the tests in my post #6763 where it says the gas generator is ignited and the temperature of the gas path was checked within the limit.

I know that the kind of test that you propose does happen, but as I understand it has happened long ago as component test.

No. Pre-burner and turbine are both tested to as near as actual operating condition as possible with the fuel and oxidizer supplied to it with different piping from those of the turbopumps.

 

[gelgoog]

Most of the time I have seen water testing of engine components they just test the turbopumps in isolation.

 

[taxiya]

Delete.