ABSTRACT

Aiming at determining the multifactorial mathematical model of mechanical drilling speed, which takes into account the overall influence of operating parameters and the drilling tool characteristics on the energy output, we have used the method of rational planning of experiments. According this method the combination of variable factors, including the axle static load Fstat , the drilling bit rotation rate n, the severity C and the damping factor β of the drilling tool occurs only once. According to this the overall multidimensional function can be presented in the form of the gain of separate dependencies on the variable factors – Vmech = Bav · f(Fstat ) · f(nb ) · f(β) · f(C) The constant factors when conducting the controlled experiment were the consumption of flushing fluid (water), the type and the diameter of the three-roller drill bit cutter and the rock hardness by the stamp.

According to the controlled experiment results, the equation of the multifactorial mathematical model of mechanical drilling speed looks as follows: V m e c h = 1.6703 ⋅ 10 − 3 ⋅ F s t a t 1.565623 ⋅ n b 0.64089277 ⋅ β − 0.03314602 ⋅ C − 4.550764 ⋅ 10 − 2 . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429227844/40b7a07c-ec3b-45ef-9702-f811a0d2466e/content/equ_chapter65_359_1.tif"/>