We show uniqueness of Ricci flows starting at a surface of uniformly negative curvature, with the assumption that the flows become complete instantaneously. Together with the more general existence result proved in [10], this settles the issue of well-posedness in this class.

Aircraft engines constitute a comp‌lex system, requiring adequate mon-itoring to ensure flight safety and timely maintenance. The best way to achieve this, is modeling the engine. Therefore, in this paper, a suitable mathematical model from engine controller design point of view, for a specific aero turbine engine is proposed by the aid of MATLAB/Simulink software. The model is capable of reduc...

Shoulder geometry of tool plays an important role in friction-stir welding because it controls thermal interactions and heat generation. This work is proposed and developed a coupled rigid-viscoplastic numerical modeling based on computational fluid dynamics and finite element calculations aiming to understand these interactions. Model solves mass conservation, momentum, and energy equations in...

rock selection in modeling and simulation studies is usually based on two techniques; routinely defined rock types and those defined by special core analysis (scal). the challenge in utilizing these two techniques is that they are frequently assumed to be the same, but in practice, static rock-types (routinely defined) are not always representative of dynamic rock-types (scal defined) in the re...

In petroleum production, Produced Water Re-Injection (PWRI) has earned much interest among disposal methods of the produced water. However, presence of the contaminants in the produced waters usually results in formation damage in well bores and their surrounding fracture systems. In the present study, modeling of external cake formation on a fracture in unsteady-state conditions i...

Representation and modeling of economic uncertainty is addressed by different modeling methods, namely stochastic variables and probabilities, interval analysis, and fuzzy numbers, in particular triple estimates. Fo-cusing on discounted cash flow analysis numerical results are presented, comparisons are made between alter-native modeling methods, and characteristics of the methods are discussed.