Numerical and Experimental Study of Microchannel Performance on Flow Maldistribution

Area of Science:

• Heat Transfer
• Fluid Dynamics
• Mechanical Engineering

Background:

• Miniaturized heat exchangers offer superior heat transfer compared to macro-scale devices.
• Enhanced performance can be achieved through reduced dimensions or induced local turbulence.
• Perturbators can lower the critical Reynolds number, improving thermal efficiency while managing pressure loss.

Purpose of the Study:

• Investigate collector performance using reduced-order modeling.
• Validate numerical models against experimental data for flow maldistribution and pressure losses.
• Compare the effectiveness of wire-net and S-shaped perturbators in microchannels.

Main Methods:

• Reduced-order modeling for collector performance analysis.
• Experimental validation of numerical models.
• Analysis of wire-net and S-shaped perturbators in microchannels.
• Measurement of flow maldistribution and pressure losses.

Main Results:

• S-shaped perturbators shift turbulent transition to lower Reynolds numbers.
• Increased microchannel resistance reduces mass flow rate deviation.
• Recirculation zones impact maldistribution patterns.
• Numerical predictions for pressure losses show good agreement with experimental data (<4%).

Conclusions:

• Perturbators effectively enhance heat exchanger performance by inducing turbulence.
• S-shaped perturbators offer a viable method for improving thermal efficiency and controlling flow.
• The study validates the accuracy of reduced-order modeling for microchannel heat exchanger design.