MEMO_AMMUNITION_MODEL.tex

MEMO AMMUNITION MODEL 17-04-2023

- Implement a angle restriction for the model.
- Implement horizontal movement and rotation in air as this could decrease impact speed.
	The drag can be higher (Kowaleczko 2009) under rotation.
- Research the drag coefficient when in water entry (drag reduction). Hot topic (Vincent 2018, Chu (2010), Aditya Jetly (2016) Thesis, Jiang (2014) Advances in Mechanical Engineering). Reduction can be order two (found by Vincent 2018 for 2d Wedge) and is assumed for this model. The air drag coefficient of aroundd 0.18 based on the terminal velocity is used for this (Re 10^6 in air based on diameter). In water higher Re. Jiang found 1.5 and said it is mainly for relatively low speed impacts (Re 10^6 based on diameter). We think this is related to a less dominant pressure over viscous drag. The drag approaches supercavitating like investigated by Logvinovich.
- Interface fluid description based on the Logvinovich model might be better for these deep penetrations. A model that looks to the cavity shape rather than the jet root.
- Implement a center of gravity based on area of the interface. 
- There is no restoring force in x-direction so we cannot involve that yet. How is this for the moment?