Numerical solution of three-dimensional problem of high-speed interaction of a cylinder with a rigid barrier, taking into account thermal effects

1994 ◽  
Vol 30 (3) ◽  
pp. 193-198 ◽  
Author(s):  
V. A. Gorel'skii ◽  
S. A. Zelepugin ◽  
V. N. Sidorov
Keyword(s):  
Numerical Solution ◽  
Thermal Effects ◽  
High Speed ◽  
Three Dimensional ◽  
Dimensional Problem ◽  
Rigid Barrier

Unsteady Loads on Supercavitating Hydrofoils of Finite Span

1966 ◽  
Vol 10 (02) ◽  
pp. 107-118
Author(s):  
Sheila Evans Widnall
Keyword(s):  
Numerical Solution ◽  
Numerical Method ◽  
Integral Equations ◽  
Digital Computer ◽  
High Speed ◽  
Three Dimensional ◽  
Numerical Results ◽  
Oscillatory Motion ◽  
Surface Theory ◽  
Finite Span

Linearized three-dimensional lifting-surface theory is derived for a supercavitating hydrofoil with finite span in steady or oscillatory motion through an infinite fluid. The resulting coupled-integral equations are solved on a high-speed digital computer using a numerical method of assumed modes similar to that used for fully wetted surfaces. Numerical results for lift and moment for both steady and oscillating foils are compared with other theories and experiments. Results of these calculations indicate that this numerical solution gives an efficient and accurate prediction of loads on a supercavitating foil.

Three-Dimensional Dynamic Simulation of Helical Compression Springs

1989 ◽  
Author(s):  
Y. Lin ◽  
A. P. Pisano
Keyword(s):  
Experimental Data ◽  
Numerical Solution ◽  
Numerical Algorithm ◽  
High Speed ◽  
Moving Boundary ◽  
Nonlinear Partial Differential Equations ◽  
Three Dimensional ◽  
Physical Reality ◽  
Dynamic Equations ◽  
Helical Springs

Abstract The dynamic equations for general helical springs are solved and classified according to the number of energy terms used to formulate them. Solutions of several sets of dynamic equations, each with a different number of energy terms, are compared with experimental data. It is found that at higher compression speeds the numerical solution with a traditional, fixed boundary represents a physically impossible situation. A moving boundary technique is applied to improve the numerical solution and bring it into agreement with physical reality. Since a convergence proof for a numerical algorithm for nonlinear partial differential equations with a moving boundary is not available, a grid study has been performed to demonstrate convergence. The agreement between the solutions of different grid sizes and the experimental data is taken to show that the numerical algorithm was convergent. This three dimensional spring simulation model can be used in the simulation of high-speed mechanical machinery utilizing helical springs, and in particular, for design optimization of automotive valve springs.

Three-Dimensional Dynamic Simulation of Helical Compression Springs

1990 ◽  
Vol 112 (4) ◽  
pp. 529-537 ◽  
Author(s):  
Y. Y. Lin ◽  
A. P. Pisano
Keyword(s):  
Experimental Data ◽  
Numerical Solution ◽  
Numerical Algorithm ◽  
High Speed ◽  
Moving Boundary ◽  
Nonlinear Partial Differential Equations ◽  
Three Dimensional ◽  
Physical Reality ◽  
Dynamic Equations ◽  
Helical Springs

The dynamic equations for general helical springs are solved and classified according to the number of energy terms used to formulate them. Solutions of several sets of dynamic equations, each with a different number of energy terms, are compared with experimental data. It is found that at higher compression speeds the numerical solution with a traditional, fixed boundary represents a physically impossible situation. A moving boundary technique is applied to improve the numerical solution and bring it into agreement with physical reality. Since a convergence proof for a numerical algorithm for nonlinear partial differential equations with a moving boundary is not available, a grid study has been performed to demonstrate convergence. The agreement between the solutions of different grid sizes and the experimental data is taken to show that the numerical algorithm was convergent. This three dimensional spring simulation model can be used in the simulation of high-speed mechanical machinery utilizing helical springs, and in particular, for design optimization of automotive valve springs.

Comparison and Synthesis of 2D+T and 3D Predictions of Non-Linear Ship Bow Waves

2013 ◽  
Author(s):  
Gabriel D. Weymouth
Keyword(s):  
Approximate Solution ◽  
Boundary Data ◽  
High Speed ◽  
Three Dimensional ◽  
Cartesian Grid ◽  
Two Dimensional ◽  
Dimensional Problem ◽  
Bow Waves ◽  
Bow Wave ◽  
Speed Up

2D+T models for the approximate solution of ship divergent waves are of interest because of the orders of magnitude speed-up that they enable. Nonlinear ship bow waves of slender high-speed vessels are investigated using 2D+T and three-dimensional Cartesian-grid simulations using the conservative Volume-of-Fluid and Boundary Data Immersion Methods to model the fluid and solid interfaces. The formulation of the unsteady two-dimensional problem in this framework is detailed and the results are shown to be quantitatively accurate only when the ship is sufficiently slender and moving at high-speed. The class of bow wave; i.e. non-breaking, spilling, or plunging: is correctly predicted by 2D+T but the location of breaking is not. These deficiencies are overcome to some extent using a Physics-Based Learning Model, which supplements the high-speed 2D+T predictions with a limited set of three-dimensional examples to produce accurate quantitative predictions.

Sign in / Sign up

Export Citation Format

Share Document