Development of an effective porthole. Report No. 2

Concerning the Determination of the Geometrical Parameters of the Optical Element of a Deep-Water Surveillance System

“…An important aspect in the design of a disk-shaped optical porthole is the selection of proper geometrical dimensions, as well as the optimal loading pattern. The following are the results of four load schemes (Figure 2, 1-4): According to studies [1], an effective solution would be a variant with a partial distribution of external hydrostatic pressure over both bases and a cylindrical surface (Fig. 1.3).…”

“…Then, with such a safety margin, we obtain the ratio h/D = 0.4, which corresponds to the thickness of the glass element h = 32 mm. However, in paper [1], based on experimental data, it was said that h/D = 0.52 ... 0.55 should be considered a good engineering solution, which corresponds to σ σ = 0.33. Therefore, based on numerical calculations, the relative thickness of the item, h/D should be chosen in the range from 0.4 to 0.55 (the height of the item cannot continuously increase due to the deterioration of optical properties).…”

“…In addition, the selection of the material of the optical element should take into account: resistance to the chemical effects of seawater; the requirements for optical components, namely, high transparency in the spectral range used, the possibility of using known technologies for processing optical materials both for obtaining transparent surfaces (grinding hardness) and for imparting the required shape. Studies on this topic are presented in papers [1][2][3][4][5][6][15][16][17].…”