Development of an experimental facility to study drag reduction and heat transfer enhancement of water flow in a channel

• Main Author: Ho, Nigel Qing Xuan
• Other Authors: Leong Kai Choong
• Format: Final Year Project
• Language: English
• Published: 2019
• Subjects: DRNTU::Engineering::Mechanical engineering
• Online Access: http://hdl.handle.net/10356/77868
• Institution: Nanyang Technological University

Drag reduction is the phenomenon in which there is an increased flow rate at a constant pressure drop or a decreased pressure drop at a constant flow rate. Drag reduction occurs due to additives being introduced in small quantities into the flowing fluid. This translates to lower pumping energy requirements, which can lead to massive energy savings for large scale projects. Drag reducing additives have been researched on for a considerable period and have cut costs significantly in industries that require liquids to be pumped over long distances, for example the transportation of crude oil or water. Drag reducing additives reduce the turbulent friction in the pipeline but also reduce the heat transfer capabilities of the liquid. This will lead to reduced efficiencies in applications such as district heating and cooling systems. Hence, this will offset some of the energy savings due to the drag reduction as a larger amount of liquid is required to maintain the same rate of cooling or heating. The objective of this project is to develop an experimental facility to evaluate the drag reduction capabilities of a surfactant when added in increasing concentrations. Passive heat transfer enhancement methods will also be explored to identify an efficient method to restore the heat transfer to its previous capabilities. The new experimental facility is 5.2 m in length as compared to 7.08 m previously. This is a 26 % decrease in total length. In addition, the facility has been tested and there are no water leakages and the Reynolds number achieved was 9000. This is greater than the Re 8000 required for fully turbulent flow, hence the facility is ready for operation.