CFD Simulation on Model of the Experimental Hybrid-Rocket Motor

• Main Authors: Lin, Jyun-Jie, 林俊傑
• Other Authors: Wu, Jong-Shinn
• Format: Others
• Language: en_US
• Published: 2009
• Online Access: http://ndltd.ncl.edu.tw/handle/37808658838550726315

碩士 === 國立交通大學 === 機械工程系所 === 97 === Hybrid-Rocket is composed by gaseous or liquid oxidizer and solid fuel. Unlike with Solid and Liquid fuel, Hybrid-Rocket has these advantages: 1.Safety 2. Insensitivity to cracks and imperfections 3.Reliability 4.Energy management 5.Fuel versatility 6.Design flexibility 7.Environmental friendliness 8.Low cost. Of course it has disadvantages like: 1.Slow regression rate 2.Low volumetric loading 3.Fuel residuals 4.Mixture ratio shift 5.Mixing/combustion inefficiencies. And because of its safety, low cost and Design flexibility, hybrid rocket is suitable for academic research. In Dr. Wu’s APPL Lab, Hybrid-Rocket research is separated into two groups, the experimental group and simulation group. And I’m in charge of the Hybrid-Rocket combustion CFD simulation, based on the model of experimental group. In the simulation, we used the simulation code “UNIC” made by Dr. Chen and his colleagues in NSPO. As for our goal, mixing ratio and thrust of Hybrid-Rocket is smaller, so they are the main factors to improve. We used C4H6 and N2O as fuel and oxidizer to finish the basic model. Then, based on this model, we changed the simulation conditions area ratio of pintle injector, port size, pre-combustion chamber size, inlet mass flow rate of oxidizer and inlet region geometry. Then we compared the results with the basic model. From the experimental results, we can see the pintle injector designed by Dr. Chen is quite useful. It maintains a low Temperature region near the pintle injector and thus the pintle injector can be reused for many times without any damage. It can also direct the oxidizer flow well into pre-combustion and fuel port region.