My master thesis is about heat transfer enhancement technique in a rectangular channel with tilted perforated baffles. I am going to apply a constant heat flux on the upper and lower surfaces of the test channel which are made of aluminum and have dimensions of (17cm*1m) and they are 3mm in thickness. Also, the tilted perforated baffles installed on the upper and lower plates in staggered arrangement as shown in the figure. In order to calculate Nusselt number, I have to get the temperature readings in different positions on the heating surface. What is your recommendation about the installation of thermocouples, knowing that the pitch equals 10 cm and the flow is turbulent?
Do I need to install thermocouples on the upper and lower surfaces or on one surface only and what is the best number of thermocouples and the satisfying position for the thermocouple junction?
I need to measure the local Nusselt numbers at different positions on the plate. @Leander Boer
I would suggest using 8-10 thermocouples spread at equal distance in 1m span starting from Inlet to Exit of the test section placed at the centre of the plate width-wise (i.e. at 17cm/2 = 8.5cm ). Further add another thermocouples on both the sides of these thermocouples i.e. towards the side walls at about 2cm inside the the wall. The number on one side should be 5-6 in each line (1 at inlet, 1 at outlet and rest spread between them at equal distance) . The similar could be followed on other side of the center-line thermocouples. So the total could be around 18-22 thermocouples.
Make sure to add minimum of 3 thermocouples at the inlet and Exit of the test section.