Chennai, Dec 12 (UNI) The Indian Space Research Organisation (ISRO) has successfully carried
out the sea level hot test of its CE20 Cryogenic Engine featuring a nozzle area ratio of 100.
The test was conducted at the ISRO Propulsion Complex at Mahendragiri in Tamil Nadu on November 29, 2024.
The performance of a multi-element igniter that is required for engine restart capability was also demonstrated during this test.
"Preparing for inflight re-ignition, full nozzle cryogenic engine (CE20) undergoes test outside vacuum chamber", it said.
Testing the CE20 engine at sea level poses considerable challenges, primarily due to the high area ratio nozzle which has an exit pressure of approximately 50 mbar.
The main concern during testing at sea level include flow separation inside the nozzle, which leads
to severe vibrations and thermal problems at the flow separation plane leading to possible mechanical damage of the nozzle.
In order to mitigate this issue, the flight acceptance tests for CE20 engines are currently being performed at the High-Altitude Test (HAT) facility, thereby adding complexity to the acceptance
testing procedure.
To reduce the complexity related to the testing at HAT, a sea level test utilizing an innovative Nozzle Protection System was devised that has paved the way for a cost-effective and less complex procedure for acceptance testing of the cryogenic engines.
Restart of a cryogenic engine is a complex process. Major challenges are vacuum ignition without nozzle closure and use of multi-element igniter. ISRO has demonstrated vacuum ignition of CE20 engine without nozzle closure in earlier ground tests. In this test, the multi-element igniter performance was also evaluated, wherein, only the first element was activated, while the health
of the other two elements were monitored.
During this test, both the engine and facility performance were normal, and the required engine performance parameters were achieved as anticipated.
The indigenous CE20 cryogenic engine developed by the Liquid Propulsion Systems Centre of ISRO is powering the upper stage of the LVM3 launch vehicle and has been qualified to operate at a thrust level of 19 tonnes.
This engine has successfully powered the upper stage of six LVM3 missions so far.
Recently, the engine was qualified for the Gaganyaan mission with a thrust level of 20 tonnes and also to an uprated thrust level of 22 tonnes for the future C32 stage, towards enhancing the payload capability of LVM3 launch vehicle.
UNI GV 1905