الفهرس 
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Abstract
For housing it is justified to divide Egypt climate into ~ree climatic zones.
* Hot dry
* WanD. dry
* Warm humid
”Menia New City”
”Tenth of Ramadan New City” ”New Ameriyah City”.
It is concluded from the temperature compared with comfort ranges for the chosen cities that there are different requirements should be considered for the successful planning and design process concerning each city.
Governmental low cost housing projects in all Egyptian new cities provide seven suggested models for the block. Many of these models have already carried out without considering the characteristics of each city and the requirements of building form and cluster.
Ventilation can serve two distinct functions in hot regions * Ventilation for enhancing comfort of the occupants.
* Ventilation for cooling the structural mass of t~e building. Controlling outdoor air with a relevant speed into a building may provide a direct physiological cooling effect and enhances the feelling of comfort when the indoor air temperature is rather warm, which called ”comfort ventilation
Localized wind movement and direction depend on the location of high and low pressure areas, the density of air, the amount
,f temperature differentials caused by shade or Sun, ~pography, Land/water formations, and ~~e position and
:ilt of the earth in respect to the Sun.
The individual differential equation is a compilation of heat transfer and fluid flow, which represent an influence on a mit-volume basis, and then both i.ply a balance or conservation, and the basis is principles of conservation of: tair mass (continuity)
t air momentum in X, Y and Z directions - u, v and w. t thermal energy - T.
The vast llajority of commercial CFO (Computational Fluid ~amics) codes use the finite volume method. The theoretical resis of the finite element method is mathematically complex, ~re so than the finite volume approach. It is claimed that ~e finite element method offers greater mesh flexibility and a JlK)re accurate solution on a given mesh than the finite vol ume method.
~e atmospheric boundary layer (ABL) is that portion of the at1llOsphere which dependent to wind speed and the earth surface roughness. The mean velocity prof ile throughout the entire depth of the neutral boundary layer may also be represented by a power law with only small errors associated with wind varying with height.
Numerical modelling of wind flow conditions around buildings lainly consists of three stages of operation: formulation stage, computation stage and validation stage.
The effect of computing parameters is addressed by considering four main factors of the computation stage: size of the computational domain, number of computational nodes, criteria of terminating the iteration process and the use of different computer system.
The solution procedures in FLOVEHT are based on the techniques of Computational Fluid Dynamics (CFO). It is concerned with the nUlllerical simulation of air flow, heat transfer and related processes such as radiation, conduction and convection. The objective of CFO provides the engineer wi th a computer-based predictive tool that enables him to analyze the air-flow processes occurring wi thin and around buildings, with the objective of improving and optimizing the design of new or existing buildings.
The length of negative zone behind the building is increased when the elevation width is increased, until the elevation width equals three times alongwind length there is no effect any more for the three different shapes, i.e. rectangular, L shape and U shape.
The negative zone length behind the building is increased proportionally with the building heights, until the height equals 1.5 of the alongwind length, and then, there is no effect after that.
The length of negative zone behind the building is increased when the building alongwind lengths are decreased, until the alongwind length equals 1/4 of the elevation, and then this values are decreased with the decreasing of alongwind length.