No abstract

To deal with any such applications, it is a must to understand the basic form and nature of the governing equations of fluid dynamics. It is imperious to fully understand the basic of numerical discretization that can be applied in equations. This paper aims to present some CFD tools that are the starting point in solving problems related to the field of fluid dynamics. During this work, we will note that anyone CFD technique will not be appropriate for all problems and the diverse mathematical nature of partial differential equations will ensure that some algorithms will best work for hyperbolic equations and others will do best for elliptic equations. In addition, this paper examines precisely how CFD techniques can be used to solve various flow problems. In other words, CFD applications requires the simultaneous knowledge of some major aspects, such as the governing flow equations and their mathematical behavior, aspects of numerical discretization of partial differential equations, also known as finite differences or of integral equations, known as finite volumes. Computational fluid dynamics has a major impact on airplane design and soon to be a critical technology for aerodynamic design with the purpose to enhance the design process for any machine that deals with fluid flow.

In the following study, experimental results are obtained from an automated stand. With the help of this experimental stand, visualization techniques such as Schlieren and Shadowgraph can be applied, to study the flame front propagation of air and inflammable gas mixtures initiation. In parallel, an infrared sensor was used to control a push-pull solenoid to open the gas escape diaphragm of the stand. To obtain the explosive gas mixture at various concentrations (between the lower explosion limit and the upper explosion limit) an original programmable mixer was used, based on computational algorithms for accurate control of stepper motors which allow attainment of air and inflammable gas flows in order to achieve a homogeneous and continuous mixture at the desired concentration. The performed experiments allow for a better understanding of the flame front production and propagation, facilitating the knowledge and optimization of the operating times from the reduction mechanisms for reducing the effects of explosions of the flammable gas-air mixtures.

Fires caused by human activities are one of the main causes of losses in terms of both human lives and material and economic capital. To prevent these losses, it is necessary to perform the needed activities of research in the area of industrial fires, as such one of the methods of achieving this, is to perform computer aided numerical simulations of fires. By this process of computational modelling, we can determine the causes of the fires, and the mechanism by which the fire has propagated and developed. Also, numerical modelling of fires, can help in the development of procedures, and norms, which we can implement, to protect the personnel and to prevent material and economic losses.

In the following paper, experimental results regarding the effect of explosion pressure are obtained from open field experiments with detonation of explosive charges. In addition, sensors that can be used for security applications for the detection of toxic and explosive compounds, as well as mobile systems for the detection of shock waves due to explosions were used to acquire more detailed results. Sensors are the main components in products and systems used to detect chemicals and volatile organic compounds (VOCs) targeting applications in several fields, such as: industrial production and the automotive industry (detection of polluting gases from cars, medical applications, indoor air quality control. The sensory characteristics of a robot depend very much on its degree of autonomy, the applications for which it was designed and the type of work environment. The sensors can be divided into two categories: internal status sensors (sensors that provide information about the internal status of the mobile robot); external status sensors (sensors that provide information about the environment in which the robot operates). Another classification of these could be: distance sensors, position sensors, environmental sensors - sensors that provide information about various properties and characteristics of the environment (example: temperature, pressure, color, brightness), inertial sensors.