Research On The Special Forest Fire-fighting Aerial Bomb's Hung-load Delivery System For Z-8 Helicopter

In recent years, forest fire prevention especially crown fire has received increasing attention as a worldwide problem. Fire-fighting bomb,which is a professional equipment of fire prevention,has been the important research direction at home and abroad. This subject originates from the important special training plan of the Fundamental Research Funds for the Central Universities with the name of" Research on Intelligent Forest Fire-fighting Bomb "( subject number: HEUCFZ1025) and the project of Harbin excellent academic leader with the name of "Intellegent Forest Fire-fighting Bomb and its special Jettisoning Set"(subject number: 2013RFXXJ2), and gets the great support and cooperation of Jiujiang Ship Fire Equipment Co. Ltd. This subject is devoted to studying a jettisoning set of fire-fighting bomb, which is hung up by Z-8 helicopter, and it meets the functional need of forest fire-fighting bomb with special design.This paper introduced the research status of forest fire prevention equipment at home and abroad and characteristics of this subject, made clear the technological superiority of fire-fighting bomb in fire prevention field. The general scheme was made by determining the workflow of bomb system and analysing the design requirements according to the actual working conditions of fire, and the application types of fire-fighting bomb and the delivering methods of jettisoning set were elaborated.This subject made a functional design of jettisoning set at first basing on crown fire and the workflow of fire-fighting bomb. The ballistic model in the falling process was builded and the simulation analysis on space motion was made, in order to find the cause of the two space motion models of ballistic system, to provide theory reference of engineering design.The mechanical design of jettisoning set concerned not only the loading and delivering of bomb, but directly affected the flight safety of helicopter. This paper modularly designed the mechanical structure of jettisoning set according to the relevant parameters of Z-8 helicopter and the different working forces, and made a static analysis on complex weldments.Considering that the jettisoning set with truss structure could easily be affected to resonance by wind load and helicopter, this paper made a modal analysis on jettisoning set and got the relevant natural frequence spectrum.Finally, the tests of bomb system were made, which mainly included static blasting test of bomb, strength test and jettison test of jettisoning set. The relevant test program and test procedure were designed, the test conclusion and existing problem were explained and improved. The results obtained further confirmed the applicability of bomb system in forest fire.