internal pressure

This paper describes a re-analysis of internal pressure and building ventilation in a single-opening enclosure ventilated by winds. The dynamics of internal pressure is governed by a nonlinear oscillation equation. An alternative semi-nonlinear approach is proposed for obtaining the amplitude and phase shift of the periodic motion, the resonant frequency and resonant amplitude. Our new approach reproduced two of the commonly used existing linearization results.

The mean and dynamic internal and external pressures of an existing building (tennis hall) and a model of the building were measured and compared. Asystematic examination was made of the effects on wind-induced internal pressure in simple geometric models of flow profile, wind direction, building dimensions, openings and leakiness. Suggestions are proposed for changes to DIN 1055 Part 4. The Canadian, American, British and Swiss Standards on wind loads are compared.

Discusses strategy for dealing with indoor air pollution in office and similar buildings, including verification of the mechanical ventilation system, measurement of building pressure, problems due to stack effect, presence of moisture. Suggests that the causes and cures of indoor pollution are diverse and surprisingly simple. Mechanical ventilation systems should be less complex, have dynamic stability and correct uncontrolled excessive moisture.

The aerodynamic forces affecting wind and rain penetration of roofs are described. They are: 1 the wind and its turbulent nature, 2 the induced pressure field, 3 the air flows in contact with the roof and 4 the characteristics of the roof (internal pressure, permeability, structure, etc).

Shows that the interior pressures in buildings are amenable to more detailed analysis than is conventionally given them and that useful information on them can be easily derived from the wind tunnel data on external pressures. The uncertainties can be expressed in parallel statistical terms. The importance of fluctuating pressures are related to the area of the opening and interior volume and a simple criterion indicates when these are likely to be important.

Presents an analytical model for the prediction of ventilation rates, internal pressures and temperatures as influenced by the combined effects of heat dissipation inside industrial buildings and natural wind action. The model inputs are external pressure distribution, pressure drop coefficients of theopenings and thermal conductance of the walls and roof assumed to be knownfrom experimental data. A simple example is worked out. It consists of a two span long building, equipped with a natural ventilation system and divided into two internal spaces differently heated.

Studies the effects of permeability on the wind loading on a building. Compares experimental results from wind-tunnel tests with theoretical methods for estimating the mean and fluctuating internal pressures for various permeability. Observations show that the internal pressure can be estimated from known external conditions in terms of mean RMS and spectral values to a reasonable level of accuracy for the case where the permeability consists of circular apertures. Effects on the external pressure distribution due to permeability are found to be significant under certain circumstances.

Reports investigation of mean and fluctuating pressure inside buildings, induced by wind using boundary layer wind tunnel and computer simulation techniques. Mean and root-mean-square fluctuating internal pressure coefficients were both found to be monotonic functions of the ratio of windward to leeward opening areas.< The case of a single windward opening was treated as a damped Helmholtz resonator.

Reports wind tunnel measurements of the wind-induced internal pressures of models of low-rise buildings of different geometry and internal volume. Three different uniform porosities (0.0 0.5 and 3.0% of the total surface area) have been examined in combination with openings in a wall ranging from 0 to 100% of that wall's area. Two terrain roughnesses were used corresponding to open country and suburban regions.< Finds that internal pressures are variable but generally lower than local external pressures.