Local heat transfer enhancement induced by a piezoelectric fan in a channel with axial flow

Late Holocene Climate Warming Events and Their Linkage to Hydraulic Engineering on the Coast of Hangzhou Bay, East China

“…To counter the seawater intrusion, a defense seawall was constructed in 50 CE, which had a history of almost 2000 years [51]. During the Tang Dynasty, coastal flooding and salinity intrusions persisted, leading to the construction of Shanyin Seawall in 686 CE and the Kuaiji Seawall in 722 CE on the south coast of Hangzhou Bay [24,25]. Subsequently, there were two more expansions to the Kuaiji Seawall.…”

“…In addition, hydraulic engineering along Hangzhou Bay reported by previous studies based on historical documents [24][25][26][27]51,52] were collated (Figure 2) for comparing with the hydrological and climatic environments recorded in the stratigraphy.…”

“…In addition, during the Eastern Han Dynasty, hydraulic engineering to manage river floods also appeared on both coasts of Hangzhou Bay. In 140 CE, Jianhu Lake was enclosed (Figure 1c) with large gates and weirs on the south bank, which is the oldest large-scale, comprehensive, hydraulically engineered structure for water storage and navigation south of the Yangtze River in China [25]. In 173 CE, the Great Xixian Levee was constructed along the south Tiaoxi River to defense river flooding and the South Lake was enclosed to store the flood water [26,27].…”

“…The coastal plain of Hangzhou Bay in East China (Figure 1) had served as a significant population center since the Neolithic period and was the location of the Liangzhu hydraulic engineering system constructed approximately 5000 years ago, which is the earliest largescale hydraulic project in East Asia (Figure 1b) [23]. During the historical period, a number of hydraulic engineering occurred here (Figure 1c), not only the construction of seawalls to defense storm tides in Hangzhou Bay but also the construction of large reservoirs/artificial lakes and river levees in the hinterland, which were used to control river floods [24][25][26]. Some researchers have suggested that the current East Tiaoxi River washing against the northwest wall of Liangzhu City (Figure 1b) was redirected following the construction of the Great Xixian Levee in 173 CE during the Eastern Han Dynasty [27].…”

Investigation of the characteristics of turbulent flow and heat transfer induced by a vibrating piezoelectric fan on asymmetrical concave surfaces

“…It is illustrated that the streaming flow induced by a piezoelectric fan possesses vortical feature and the attainable flow rate is tightly dependent on the vibration parameters (such as vibration frequency, amplitude and mode shape), [7][8][9][10] its geometric parameters 8,[11][12][13] and operating environment. [14][15][16][17][18] Of particular is that the transient 3-D vortex structures emanated from the trailing and side edges and the process of breakdown have been fully captured by Ebrahimi et al 19 and Oh et al 20 On account of its pseudo-jet impingement role, plenty of investigations have also been made to the reveal the heat transfer performance of piezoelectric fan. [21][22][23][24][25][26] Extensive literature research suggests that most of the studies on air cooling technology using piezoelectric fans are focused on heat dissipation surfaces with simple structure.…”