Revisiting the ‘Venturi effect’ in passage ventilation between two non-parallel buildings

A recent study conducted by Blocken et al. (Numerical study on the existence of the Venturi effect in passages between perpendicular buildings. Journal of Engineering Mechanics, 2008,134: 1021-1028) challenged the popular view of the existence of the ‘Venturi effect’ in building passages as the wind is exposed to an open boundary. The present research extends the work of Blocken et al. (2008a) into a more general setup with the building orientation varying from 0° to 180° using CFD simulations. Our results reveal that the passage flow is mainly determined by the combination of corner streams. It is also shown that converging passages have a higher wind-blocking effect compared to diverging passages, explained by a lower wind speed and higher drag coefficient. Fluxes on the top plane of the passage volume reverse from outflow to inflow in the cases of α=135°, 150° and 165°. A simple mathematical expression to explain the relationship between the flux ratio and the geometric parameters has been developed to aid wind design in an urban neighborhood. In addition, a converging passage with α=15° is recommended for urban wind design in cold and temperate climates since the passage flow changes smoothly and a relatively lower wind speed is expected compared with that where there are no buildings. While for the high-density urban area in (sub)tropical climates such as Hong Kong where there is a desire for more wind, a diverging passage with α=150° is a better choice to promote ventilation at the pedestrian level.

A parallel data assimilation model for oceanographic observations

In this paper we describe the development of a program that aims at the optimal integration of observed data in an oceanographic model describ

Aligning IS programs with industry: linking business analysis curricula design with the professional body

Aligning information systems (IS) solutions with business goals and needs are crucial for IS activities. IS professionals who are able to work closely with both the business and technical staff are key enablers of business and IT alignment. IS programs in higher education (HE) institutions have a long tradition of enabling graduates to develop the appropriate skills needed for their future careers. Yet, organizations are still having difficulty finding graduates who possess both the knowledge and skills that are best suited to their specific requirements. Prior studies suggest that IS curricula are often ill-matched with industry/business needs. This study reports on the business analysis curricula (re) design which was undertaken to align it with a key professional body for the IS industry. This study presents the approaches taken in the (re) design of the module, and provides a discussion of the wider implications for IS curricula design. The results show a positive outcome for the HE and professional body partnership.