Page 100 - Undergraduate Research Opportunities Program Proceedings 2017-18

School of Engineering
Department of Mechanical & Aerospace Engineering

Supervisor: LI Larry / MAE
Student: KIMISHIMA Hiromi / MAE Course: UROP1100, Spring

Compared with the more conventional bi-wing configuration, a tandem-airfoil configuration, with one airfoil at the front
and one at the back, can offer improved aerodynamic performance, but only if the stagger and gap distances are
appropriately chosen. Furthermore, the lift generated by the two airfoils would be farther apart along the longitudinal
axis, resulting in improved stability and control. In this project, the design principles, merits, drawbacks and state-of-the-
art knowledge of the tandem-airfoil configuration have been examined, with a view towards developing a new design
framework by which tandem-airfoils can be optimized for use in the next generation of micro aerial vehicles (MAVs).
Various diagnostic methods, ranging from direct force measurements to particle image velocimetry, were explored
under different operating conditions, including when the airfoil is stationary, plunging or pitching – or a combination of
the three. An extensive database was constructed to record the aerodynamic conditions explored in previous
experiments and numerical simulations, laying the foundation for a future feasibility study and prototype development
of a tandem-airfoil MAV.

Forced Synchronization of a Capillary Jet for 3D Printing Optimization

Supervisor: LI Larry / MAE
Student: FAN Zhiyuan / MAE Course: UROP1100, Fall

To better understand the physical process of droplet formation, the mean formation frequency of water droplets from a
capillary tube is examined over a wide range of flow rates (Q) and nozzle diameters (D). The mean formation frequency
is found to be predictable within a broad range of Bond numbers (G), i.e. a broad range of tube diameters, and Reynolds
number (Re)/Weber number (We) from virtually zero to pure jetting. A universal scaling is proposed to predict the
natural frequency of droplet formation, based on the Strouhal number (St), G, Re and We. It is found that for pure water,
i.e. for a small subset of Ohnesorge numbers (0.0030 < Oh < 0.0052), the mean droplet formation frequency is well
predicted by the proposed scaling.

Universal Scaling Laws for Droplet Formation in Capillary Jets
Supervisor: LI Larry / MAE
Student: FAN Zhiyuan /AERO Course: UROP1100, Spring
PARK Jungjin / MAE UROP1100, Spring

The natural frequency of droplet formation from a capillary jet of water is examined over a wide range of flow rates (Q)
and nozzle diameters (D). The mean natural frequency is found to follow a universal scaling relationship within a wide
range of Bond numbers (G), Reynolds numbers (Re) and Weber numbers (We) – from very low flow rates to pure jetting.
The scaling relationship contains the Strouhal number (St) and G with Re and We corrected by G. The proposed scaling is
benchmarked against existing literature, and shows potential to be robust in a variety of flow configurations.

Supervisor: LI Larry / MAE
Student: WU Sen / AERO Course: UROP1000, Summer

A theoretical study of the incompressible aerodynamics of soft morphing wings has been carried out in this summer
UROP project. In contrast to mainstream computational and experimental studies of bio-inspired soft morphing wings,
this project aims to identify general solutions of the acceleration profile of the material points of soft morphing wings,
with boundary conditions defined by membrane and wing roots. A simple theoretical problem with direct physical

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