shielding

Describes typical town centre developments in which a problem of wind environment has arisen, and gives a brief account of the investigation of specific cases. Summarises broad conclusions of 20 special cases. Describes series of investigations intoair-flow around small groups of idealised model buildings and compares model with full-scale measurements. Outlines design method for use in planning layout of small groups of buildings. Discusses future research needs.

Describes the ventilation of buildings by analogy with electric circuits and derives expressions for ventilation with and without flow through ducts in the roof. Finds that in general ventilation rate will vary linearly with wind velocity. Considers the effect of shelter belts on wind velocity and derives expression for sheltered ventilation rate. Suggests that eddy motion caused by shelters may be important. Gives measurements made on models in wind tunnels to show the affect on wind pressure of sheltering buildings at various distances.

Describes measurements made of wind speed and direction and pressure differences across the exterior walls of two multi-storey buildings in Montreal. Regression coefficients are obtained and show better correlation for higher levels than forlower ones and for the taller building "A" than building "B", indicating that shielding by adjacent buildings has an important effect. The variation in wind velocity between the site and a meteorological station was recorded.

Reports measurements made of wind pressures on a multi-storey building in London. Autocorrelations and power spectra were computed for the 48 pressure transducers and showed noticeable fluctuations in the pressures on the windward face, Possibly caused by a cushioning effect in front of the building "leaking" away at regular intervals. Mentions effect of the permeability of building. Comparisons made with wind tunnel tests improved when surrounding buildings were taken into account. Recommends design gust durations for various sizes of building.

Conducts series of tunnel tests to examine ways in which wind influence air infiltration energy losses in housing. Develops qualitative model for air infiltration based upon a linear relationship between air flow and pressure difference across walls and roof surfaces. Tests a variety of wind-house orientations with the model. Assesses and compares sheltering effects provided by solid fences, adjacent houses and tall evergreen trees. NOTES See also later study by Mattingly et al. abstract no.187