Identifier

etd-07042016-220053

Degree

Master of Science in Civil Engineering (MSCE)

Department

Civil and Environmental Engineering

Document Type

Thesis

Abstract

This thesis aims to evaluate the feasibility of solar panels to be used as aerodynamic mitigation devices to reduce roof suction caused by high-speed winds on flat-roof, low-rise buildings. Roof suction is caused by negative pressures resulting in uplift on the roof, due to the wind passing over the sharp edges of the roof. Suction is a common cause of failure for these types of flat-roof, low-rise buildings during extreme wind events such as hurricanes, as the uplift force can cause the roof to separate from the building. A variety of mitigation devices have been proposed in the literature to mitigate this failure mode, which are expanded upon in the literature review. Solar panels would be a convenient medium to use as a mitigation device as the demand for green energy grows. The solar panels can be arranged around the roof’s edges which would eliminate the sharp corners that cause separation and suction on the roof. The ability of the panels to decrease the suction on the roof was tested in two ways. The first was a flow visualization study, where sand was used to show the flow patterns on the roof, with the removal of sand being a visual indication of suction. The second method required that pressure taps be added to the building, so that the pressure with and without solar panels could be recorded. Both of these tests demonstrated that the addition of the panels was beneficial to decreasing the suction on the roof. The panels reduced peak suction, as well as decreasing the range of pressures the roof was subjected to, resulting in a more even distribution of the pressure. The pressure measurements were used to calculate the pressure coefficients on the roof, which were compared to the ASCE Standard. The ASCE Standard was found to be less conservative than the pressure coefficients, with the wind tunnel tests having more extreme values. An ANSYS Fluent model of the bare-roof building was also created for comparison with the open jet wind tunnel tests, and was run through ANSYS’s Large Eddy Simulation (LES). This produced a qualitatively similar pressure coefficient distribution to the wind tunnel test, but it cannot be compared directly since the LES contour is a snapshot of the roof pressure coefficients rather than a computed result from the time history, like the open jet wind tunnel results. However, ANSYS produced a time history of the lift coefficients, so that was plotted and compared with a graph of the lift coefficient from the wind tunnel test. The resulting graphs were similar, as was the mean value for the lift coefficient.

Date

2016

Document Availability at the Time of Submission

Secure the entire work for patent and/or proprietary purposes for a period of one year. Student has submitted appropriate documentation which states: During this period the copyright owner also agrees not to exercise her/his ownership rights, including public use in works, without prior authorization from LSU. At the end of the one year period, either we or LSU may request an automatic extension for one additional year. At the end of the one year secure period (or its extension, if such is requested), the work will be released for access worldwide.

Committee Chair

Aly, Aly-Mousaad

DOI

10.31390/gradschool_theses.4205

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