Water hammer induced problems in high-rise buildings

78 p.This study investigates the common causes of noise and vibration problems in domestic water pipeline systems, particularly those supplying high-rise buildings. The study was initiated partly in response to numerous complaints from residents of high-rise apartments about their frequent bad encounters with water hammer induced noise and vibration problems. The common mechanisms which could generate vibration and noise in liquid conveying pipelines are firstly reviewed.RP11/98

Flow and entrainment characteristics of density stratified liquids in a slotted compartment induced by a submerged flow stream

This project investigates the entrainment characteristics and feedback mechanisms in mixing layer oscillations induced by a flow beneath a rectangular compartment. An approximate unfied equation was derived for estimating the mixing rates across a density interface in rectangular and circular tanks with partially open bottoms, induced by a submerged flow stream below tanks

Impact of rainwater from buildings without roof gutters

To investigate the impact force of rainwater coming off from roofs without gutters as compared to the impact force of natural rain

Performances of rainfall-runoff models calibrated over single and continuous storm flow events

Accurate parameter estimation is important for reliable rainfall-runoff modeling. Previous studies emphasize that a sufficient length of continuous events is required for model calibration to overcome the effect of initial conditions. This paper investigates the feasibility of calibrating rainfall-runoff models over a number of limited storm flow events. For a subcatchment having a moderate influence from initial soil moisture conditions, this study shows that rainfall-runoff models could still be calibrated reliably over a set of representative events provided that the events cover a wide range of peak flow, total runoff volume, and initial soil moisture conditions. This approach could provide an alternative calibration strategy for a small watershed that has a limited data length but consists of runoff events with a wide range of magnitudes. Compared to continuous-event calibration, event-based calibration appears to perform better in simulating the overall shape of hydrograph, peak flow and time to peak. However, continuous-event calibration was found to be more reliable in providing runoff volume, suggesting that continuous-event calibration should still be used when runoff volume is the main concern of a study