The exit area ratios of these calculating sections are equal to 50, 75, 100 and 144. A semilogarithmic practical formula of the radiation view factor from inside wall to exit area is given also with very high precision.
Analyses of the effect of uncertainties in view factors on the radiation heat transfer show that strict enforcement of view factor closure constraint can greatly reduce the sensitivity of the results to the errors in view factors.
Then a boundary integral equation without solid angle coefficient can be deduced by connecting integral equations inner and outer the calculation domain. The velocity potential on the body can be obtained by solving the boundary integral equation descritised by HOBEM. Through the movement equation of rigid body, the response amplitude can be obtained.
Rationalization of general formulas for angle factors
General formulas are derived for the average angle factors of volumetric and surface zones involving only a single fourfold integral, and these formulas are therefore the most rational for numerical solutions.
Approximate angle factors for two-dimensional problems
We have found the approximate intermediate functions for an isotropic incident flow by means of which  many angle factors have been expressed.
A plan to expand these placement options by allowing the user to enter surface angle factors is being investigated.
Two geometrical factors, the circumsolar view factor and the isotropic view factor for calculating solar radiation, have been proposed.
The energy budget of man is computed and used to assess the microclimatic variation that can occur in a downtown urban environment through the effects of direction of exposure and open sky view factor.
It appears that, in small water bodies, the total amount of incoming long wave radiation is sensitive to the sky view factor.
An approximate sky view factor (SVF) has been developed, which is capable of estimating the mean rate of net longwave radiant energy loss from urban street canyons.
For the calm case, modelling shows that urban-park differences of sky view factor (ψs) and thermal admittance (μ) are the relevant properties governing the park cool island (PCI) effect.
Then, the difference between the tilt angles of the ocular rotation axis during upward and downward viewing was determined and divided by the difference of vertical eccentricity ("tilt angle coefficient").
The influence of the stratification on the plume angle coefficient is studied, and compared with the results related to a homogeneous environment, obtained elsewhere.