[quote name='vasu_ray' date='07 March 2010 - 10:56 AM' timestamp='1267939126' post='104924']
From the interview with VK Saraswat from this link,
[url="http://www.deccanchronicle.com/op-ed/%E2%80%98us-still-denying-us-technology%E2%80%99-866"]http://www.deccanchr...gy%E2%80%99-866[/url]
here is an excerpt,
"Q. Are we going to see the Hyperplane test flight happen any time soon?
A. We faced a problem in high-temperature materials for the scramjet engine. We needed to run the engine for 20 seconds, but could do it only up to three seconds. We were denied imports of the material required. So, we launched a separate programme and developed three materials. We have now been able to reach 20 seconds twice. We want to do five to six more ground tests. We expect to be able to do the first test flight by the end of the year."
what are the reasons that ISRO requires 7 secs of test flight while DRDO fixes it at 20 secs and aren't these time values way smaller to be ramped up for practical flights if the materials can't withstand beyond?
if these materials are so exotic how are they comfortable with abandoning them in the ocean (citing economic reasons) after the test flights?
[/quote]
ISRO's 7 second is for passive test and that is first step to engine realization, and penultimate for first hot test (with fuel) which is expected to be of longer duration to account for operating phase.
Also ISRO's approach with cryogenic fuel allows option to cool critical part using the cryo fuel (regenerative cooling).
India and Japan were the leaders (theoretical and experimental work) in scamjet propulsion for many decades, but US was first to test fly their experimental scram engine. Will be a mistake to discount India.
------------------- Added later --------
As for DRDO, one can easily find on web pics of full scale mockup of HSTV. So it is not just 20 second on lab test bench.
From the interview with VK Saraswat from this link,
[url="http://www.deccanchronicle.com/op-ed/%E2%80%98us-still-denying-us-technology%E2%80%99-866"]http://www.deccanchr...gy%E2%80%99-866[/url]
here is an excerpt,
"Q. Are we going to see the Hyperplane test flight happen any time soon?
A. We faced a problem in high-temperature materials for the scramjet engine. We needed to run the engine for 20 seconds, but could do it only up to three seconds. We were denied imports of the material required. So, we launched a separate programme and developed three materials. We have now been able to reach 20 seconds twice. We want to do five to six more ground tests. We expect to be able to do the first test flight by the end of the year."
what are the reasons that ISRO requires 7 secs of test flight while DRDO fixes it at 20 secs and aren't these time values way smaller to be ramped up for practical flights if the materials can't withstand beyond?
if these materials are so exotic how are they comfortable with abandoning them in the ocean (citing economic reasons) after the test flights?
[/quote]
ISRO's 7 second is for passive test and that is first step to engine realization, and penultimate for first hot test (with fuel) which is expected to be of longer duration to account for operating phase.
Also ISRO's approach with cryogenic fuel allows option to cool critical part using the cryo fuel (regenerative cooling).
India and Japan were the leaders (theoretical and experimental work) in scamjet propulsion for many decades, but US was first to test fly their experimental scram engine. Will be a mistake to discount India.
------------------- Added later --------
As for DRDO, one can easily find on web pics of full scale mockup of HSTV. So it is not just 20 second on lab test bench.