Denel Dynamics interns have developed a nose cone to reduce drag and thus increase the range of the Umkhonto infrared guided missile by more than ten kilometres. The expendable nose cone will be fitted to the Umkhonto EIR surface-to-air weapon.
This was revealed during the Denel Dynamics Interns Show and Tell last week. Intern J Carelse, systems engineer on the project, said the aim was to design and build a disposable nosecone for the Umkhonto extended range (EIR) missile, with the understanding that reducing drag would increase range. The missile has a rounded nose housing its infrared seeker, but the addition of a sharply pointed nose cone significantly reduces drag. As the missile only uses its seeker in the terminal phase (the last three kilometres to the target), covering it with an aerodynamic cone poses no problems regarding target acquisition.
Carelse said it was vital for the nose cone to safely detach from the missile without damaging the missile body, guidance fins or seeker head. It also has to cope with Mach 2+ flight and 30 g manoeuvres. He said only one other missile design in the world uses a detachable nose cone.
The new nose cone was developed in 11 months at a cost of R150 000 and weighs less than five kilogrammes. As the Umkhonto EIR is not yet available, the Denel Dynamics team of nine interns used the standard Umkhonto to integrate the new nose cone.
The design that was chosen splits the cone into two parts. Pyrotechnics eject a small nose cap, which allows oncoming air to force the two sections apart. The whole assembly is attached to the missile by pins.
Due to a lack of resources, the interns were not able to fully test the nose cone’s separation and clearance, both physically in a wind tunnel or with computational fluid dynamic (CFD) computers, but basic simulations showed that range would increase by at least ten kilometres.
Denise Wilson, Denel Dynamics deputy chief executive, said that the nose cone has been on the cards for a while and will be incorporated onto future missiles. This should increase range from 25 to 35 kilometres for the Umkhonto EIR.