For energy efficient restoration of historical buildings, especially historic monuments of international importance such as the Viipuri Library by Alvar Aalto (1898 -1976), new analytical tools are needed. Of interest to this research is the evaluation of air movement within this building due to spatial composition, which can also prove very useful in helping architects determine how best to renovate and restore historical buildings. The objective is to analyze how radiant heating and passive cooling are currently exploited in the Viipuri Library. The knowledge will be useful to restore this historical building to function efficiently while ensuring that the existing mechanical ventilation systems and natural convective flows work well together after restoration. Computational fluid dynamics will be used to model, simulate and predict multiple environmental conditions to examine spatial layout effects on the ability of natural ventilation to maintain a comfortable thermal environment and acceptable rates of ventilation. The preliminary results demonstrate that airflow and thermal effects can be predicted and validated for any set of conditions, such as specifying which windows or doors are open, and the ambient conditions exterior (e.g., wind and air temperature) and interior (e.g., radiant pipes) to the building. Keywordscomputational fluid dynamics, energy efficiency, free flow open space, natural ventilation,

Double wall cooling is a very effective technique for increasing heat transfer in hot gas path components utilizing a narrow channel near the surface of the component. Multiple techniques exist to increase the heat transfer within the narrow channel, including the use of impingement jets, turbulators and microchannels. A preliminary study has been performed using computational fluid dynamics (CFD) to determine the heat transfer benefits of double wall cooling technology when compared to a smooth wall square channel and a ribbed wall square channel. Conjugate CFD simulations of flow through an aluminum channel were performed to include the effects of conduction through the solid and convection within the main channel. The design for the preliminary study consists of a square main channel and a narrow impingement channel connected by a series of holes creating impingement jets on the outer surface of the impingement channel. The study examines multiple parameters to increase heat transfer without increasing the pumping power required. The parameters studied include diameter of impingement jets, jet-to-jet spacing, number of impingement jets, and jet-to-wall spacing. Results show that the impingement channel height-to-diameter ratio has a strong impact on heat transfer effectiveness. This study also provides a new optimization methodology for improving cooling designs with specific targets.

In an effort to address residential energy needs and find ways to improve energy utilization of homes, heating and passive cooling was examined by using computational fluid dynamics. The Esherick House, whose spatial composition was intentionally designed for natural ventilation, was modeled and simulated for different environmental conditions. The simulations were used to examine spatial layout effects on the ability of natural ventilation to maintain a comfortable thermal environment. Results for the heating and passive cooling scenarios compared the effects of the temperature and velocity fields when the environmental conditions were changed. For a typical summer day, it was found that the entire house cooled quickly when a breeze was modeled to enter a few windows, both with and without solar heating. The heating scenario for a winter day modeled the two fireplaces, one located on the first floor in the great room and one on the second floor in the master bedroom. It was found that the temperatures on the second floor were too high and too low on the first floor for acceptable levels of thermal comfort. Keywordscomputational fluid dynamics, energy efficiency, free flow open space, natural ventilation, residential dwellings Article History