vivek_ahuja wrote:Kanson wrote:I think, the range is restricted by Software rather than the fuel capacity. Pillai commented of placing fuel tank in the forward section(diffuser?) so left over fuel adds to the explosive effect.
Probably just behind the warhead. They might have moved the bulk electronics in the diffuser section prior to the combustor and moved the fuel into the isolator-diffuser section behind the warhead. Very curious though: Was this part of the design modification beyond the Yakhont that turned into the Brahmos?
No, fuel tank is ahead of warhead. Understanding is it was "moved forward". Yakhont was not advertised as Kinetic weapon but Brahmos is; justifies the forward movement of fuel tank. Highest (cruise?) velocity for Yakhont is advertised as 750 m/s whereas for Brahmos it is around 850 m/s.
vivek_ahuja wrote:Kanson wrote: This can be seen in one of the Brahmos test video where a ship catches fire on impact. Yakhont is credited to have more range than 300 km. If i'm not hallucinating, the Brahmos missile body is more streamlined, probably increasing the internal volume.
Might add 10% more range or so. Not much unless the propulsion has been completely revamped inside and new materials added for the combustor. Again:
was any such modification done beyond the Yakhont? If not, we should not assume so.
Official figures:
Yakhont @ 3000 tons, length 8.9m and dia 0.72m; Brahmos @ 3000 tons, length 9m and dia 0.7m. Further Brahmos body is made of composites.
vivek_ahuja wrote:From the understanding of Pillai's statement, I think, missile hits the target at Mach 3 only irrespective of the profile it was flown. When the ramjet kicks in the missile is in Mach 2 speed.
Actually, the missile fins and inlet sections point heavily towards a M2.5-3.5 range design. Anything else and you would be flying inefficient. Essentially put, the fins aspect-ratio times the Prandtl-Glauert compressibility correction factor squared would give you an indication of high-sweep supersonic wings with arbitrary sweep and taper: if this product is less than 3, you will see increasing CL-alpha curve slopes and damping-in-roll characteristics for decreasing sweep. Otherwise, if this product is greater than 3, you will see the reverse trend. Thus, if you were designing a missile and had selected a cruise mach number, a higher than required sweep would be inefficient for that above factor being less than 3. For the Brahmos, the design point comes out Mach ~3. Fly lower, and you are not using the fins efficiently. Fly higher, same scenario.
Same problem with the inlet. Based on image analysis of the inlet angles, I can tell that we are looking at around M2.5-M3 type inlet based on axi-symmetric shock charts. Fly lower, and you are causing spillage around the inlet lip. Fly higher, you are causing a shock inside the missile! Not good.
Have you done comparative analysis of P-700 Granit, Yakhont and Brahmos? If so, is there any inference?
vivek_ahuja wrote:It all depends on how you measure the Mach number. If its referenced to sea level conditions, the Brahmos cruise altitude of around 14000m would mean that the sonic velocity ratio is 1.2. In other words, what would be Mach 2.5 on the ground would actually be seen by the Brahmos as Mach 3, i.e. its design point cruise condition.
Then, when it goes back down to sea level, it must accelerate to its design point condition from Mach 2.5 to Mach 3. In doing so, it would give credence to those reports commenting on acceleration during terminal maneuvers for such supersonic cruise missiles.
Brahmos advertise the max. speed is between 2.5 to 2.8 Mach and not as 1.5 to 2.8. Further as per Brahmos Corp.
entire flight envelope is in high supersonic speed. I guess, no one refers the speed Mach 1.5 as high supersonic. So it is 2.5 to 2.8 or whatever.
If we take 2.5 as the max. speed @ alt. 10m then @ 15000m it is around 2.8 Mach or exactly 2.88 Mach(This matches with News reports). Brahmos Corp. says, Brahmos missile is 3 times the speed of subsonic missile. So ~0.8 Mach * 3 = ~ 2.5 Mach, it matches. But then Exocet speed is 0.9+ Mach. Sizzler/Klub's terminal speed is reported to be 2.9 Mach.
As you say, purposely there could be misrepresentation or information blackout. There is always a possibility of terminal speed be different from cruise speed. If Klub can do 2.9 Mach, there is every possibility of Brahmos having similar terminal speed. BTW, Brahmos max alt is 15000m against 14000m for Yakhont.
vivek_ahuja wrote:That said, I think the comment on leftover fuel must be in respect to the fact that not all engagements would take place at maximum range of the missile. In that case, if you were to hit a target short of max range, the leftover fuel would add to the explosive effect.
Here is the case, where the limitation of range is due to MTCR restriction rather on missile design. If designing such missile which is known to do waypoint dance and terminal manoeuvres and range limited only by MTCR restriction, the necessary fuel load needed will be taken care of. Unless there is a substantial fuel left over in maximum number of scenarios, we wouldn't have taken the trouble of moving the fuel tank forward. I'm just answering to your less than 100 km interpretation. JMT.
