Answer:
1964
Explanation:
It was discovered in 1964 when a pair of Geiger counters were carried on board a sub-orbital rocket launched from New Mexico.
Three different cases are computed to clarify the possible influence of the jet Reynolds number. The Reynolds number Re = V0e/ν is set to 3000 for case (I), 7500 for case (II) and 13500 for case (III). The nondimensional time step ΔtV0/e is fixed to a value which ensure the stability of the numerical scheme (CFL< 0.3). For the largest Reynolds number simulation (Re = 13500), we have to mention that only mean quantities are here reported since insufficient integration times are yet available for this case.
The length of the horizontal direction must be large enough to capture the two large recirculations on each side of jet and to limit the influence of the buffer domain inside of the domain of interest. Preliminary bidimensional simulations have been used to test the influence of the length of the horizontal direction. We concluded that a value of Hx/e = 40 is sufficient. In the framework of air curtain applications, the opening ratio is fixed to 10 for all cases. The choice of the length of the homogeneous direction (Oz) is less obvious. Indeed, the periodic boundary conditions along the homogeneous direction are justified only if the transverse dimension Hz is large enough to capture the largest structures of the flow. Consequently, the fluctuations must be practically decorrelated on a half-period (Hz/2). In the absence of two point correlations available in the literature for plane jets with short impingement distance, we considered successively two different transverse dimensions: Hz/e = π in accordance with the simulations of Hoffmann and Benocci (1994); Voke et al. (1995), then a double dimension Hz/e = 2π. Note that Cziesla et al. (2001) set the length of the homogeneous direction to 2. Beaubert and Viazzo (2001) note an overlapping problem on the transverse two-point correlations of the different velocity components in the plane of symmetry of the jet for the smallest width. Therefore, a width of 2π for the transverse direction is rather advised for the ratio Hy/e = 10 and in this range of Reynolds numbers. Table 1 contains the characteristics of the three simulations.
Answer:
Plastic deformation, irreversible or permanent. Deformation mode in which the material does not return to its original shape after removing the applied load. This happens because, in plastic deformation, the material undergoes irreversible thermodynamic changes by acquiring greater elastic potential energy.
Elastic deformation, reversible or non-permanent. the body regains its original shape by removing the force that causes the deformation. In this type of deformation, the solid, by varying its tension state and increasing its internal energy in the form of elastic potential energy, only goes through reversible thermodynamic changes.
Answer:
they all use scientific knowledge to solve a problem
Explanation:
Engineers are professional who make use of the scientific technique or knowledge to provide a solution to the problems of the society.
They are well qualified to provide solutions or make some projects or products which makes life easier.
There are various engineers belonging to the various fields and sectors. They are the civil engineers who give expertise mainly in the construction sector making multi story buildings, bridges using their scientific knowledge, there are mechanical engineers who build various engines to make life easier using mathematical tools and scientific techniques, then there are electrical engineers who basically provide solutions to the electrical sectors, chemical engineers use their knowledge to help people and the society to build and design the fuels, foods, chemicals, pharmaceuticals,etc.
