FLUID MECHANICS GROUP
Department of Mechanical Engineering
National University of Singapore
T. T. Lim 
Ph.D., B.E (Hons).
University of Melbourne, AUSTRALIA.

T. T. Lim received his B.E.(Hons) and Ph.D. from the University of Melbourne, Australia.  He spent two years as a Research Associate at NASA Ames Research Center, USA, before returning to the University of Melbourne.  He joined the National University of Singapore in 1993. 


Tel:      (65) 6516-6350
Fax:     (65) 6779-1459
Email:  mpelimtt@nus.edu.sg

Current Appointment:
Professor

Research Interests:
Vortex dynamics  
Swirling flow
Bluff body aerodynamics
Unsteady aerodynamics
Flow visualization
 

*Selected Publications

*Video Gallery

*Flow Gallery

*Quotations

 

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Selected Publications

(a) BOOK



(1) Smits, A.J.  & Lim, T. T. (2000). Flow Visualization: Techniques and Examples, Imperial College Press. 

(b) CHAPTERS IN BOOKS

(1)  Lim, T. T. & Nickels, T.B. (1995). Vortex Rings.  In Fluid Vortices.  Editor:  Sheldon I. Green,  Kluwer Academic Publishers. 

(2)  Lim, T. T. (2000).  Smoke and Dye Visualization.   In Flow Visualization: Techniques and Examples.  Editors: A.J. Smits and T. T. Lim,  Imperial College Press.

(c) INTERNATIONAL JOURNALS

(1)  Lim, T. T. & Nickels, T.B (1992).  Instability and reconnection in the head-on collision of two vortex rings.  NATURE, Vol. 357. 

(2)   Kelso, R.M., T. T. Lim & A.E. Perry (1996).  An experimental study of a round jet in a cross-flow. J. FLUID MECH. Vol. 306. 

(3)   Lim, T. T. (1997).  On the role of Kelvin-Helmholtz-like instability in the formation of turbulent vortex rings.  FLUID DYNAMICS RESEARCH, Vol. 21. 

(4)  Lim, T. T. (1997).  A note on the leapfrogging between two coaxial vortex rings at low Reynolds numbers. PHYS FLUIDS, Vol. 9, no: 1. 

(5)  Lim, T. T. (1998).  On the breakdown of vortex rings from inclined nozzles.  PHYS FLUIDS,  Vol. 10, no:7. 

(6)  Kelso, R.M., T. T. Lim & A.E. Perry (1998).  New experimental observations of vortical motions in tranverse jets.   PHYS FLUIDS,  Vol.10, no:9. 

(7)  T. T. Lim, Y.T. Chew and Xiao Qing (1998).  A new flow regime in a Taylor-Couette flow.  PHYS FLUIDS, Vol. 10,  no:12.

(8)  S. C. Luo, T. T. Lim, K. B. Lua and H. T. Chia, E. K. R. Goh  and Q. W. Ho (1998).  The effects of an elliptical tip on the flowfield around an axi-symmetric body at high angle of attack.  AIAA JOURNAL, Vol 36, no:10. 

(9) T. T. Lim, T.H. New and S.C. Luo (2001).  On the development of large-scale structures of a jet normal to a cross flow. PHYS FLUIDS, Vol. 13.

(10) T.T. Lim, K.B. Lua  and S.C. Luo (2001).  Role of tip and edge geometry on vortex asymmetry, AIAA JOURNAL, Vol. 39.

 
(11) Xiao Q, Lim TT, Chew YT (2002).  Second Taylor vortex flow: Effects of radius ratio and aspect ratio, PHYS FLUIDS, Vol. 14 .

(12) T.H. New, T. T. Lim and S.C. Luo (2003).  Elliptic jet in cross flow, J. FLUID MECH. Vol. 494.

(13) T.H. New, T. T. Lim and S.C. Luo (2004).  A flowfield study of elliptic jets in a cross flow using DPIV technique, EXP. FLUIDS, Vol. 36.

(14) J. E. Cater, J. Soria & T. T. Lim (2004).  The interaction of the piston vortex with a piston-generated vortex ring, J. FLUID MECH., Vol. 449.

(15) T. T. Lim and K.S. Tan (2004).  A note on power-law scaling in a Taylor-Couette flow.  PHYS FLUIDS., Vol. 16.

(16) T. T. Lim, T.K. Sengupta & M. Chattopadhyay (2004). A visual study of vortex-induced sub-critical instability on a flat plate laminar boundary layer, EXP. FLUIDS., Vol. 37.

(17) T.T. Lim & Y.D. Cui (2005). On the generation of a spiral-type vortex breakdown in an enclosed cylindrical container, PHYS FLUIDS., Vol. 17.

(18) T.H. New, T. T. Lim & S.C. Luo (2006).  Effect of jet velocity profiles on a round jet in cross flow. EXP. FLUIDS, Vol. 40.

(19) J.M. Lopez, Y.D. Cui & T.T. Lim (2006). Experimental and numerical investigation of the competition between axisymmetric time-periodic modes in an enclosed swirling flow, PHYS FLUIDS, Vol. 18.

(20) Y.T. Ng, S.C. Luo, T. T. Lim & Q.W. Ho (2006). On swirl development in a square cross-sectioned, S-shaped duct, EXP. FLUIDS, Vol. 41.

(21) T.T. Lim, T.H. New & S.C. Luo (2006). Scaling of elliptic jets in cross-flow, AIAA JOURNAL,Vol. 44.

(22) Y.D. Cui, T.T. Lim & H.M. Tsai (2007). Control of vortex breakdown over a delta wing using forebody spanwise slot blowing, AIAA JOURNAL, Vol. 45. no:1

(23) H. Singh, E.S. Ang, T.T. Lim & D.W. Hutmacher (2007). Flow modelling in a novel non-perfusion conical bioreactor, BIOTECH & BIOENG., Vol. 97, no:5

(24) K.B. Lua, T. T. Lim, K.S. Yeo & G.Y. Oo (2007). Wake-structure formation of a heaving two-dimensional elliptic airfoil, AIAA JOURNAL, Vol.45, no:7.

(25) Sengupta, Lim, Sajjan, Ganesh & Soria (2007).  Accelerated flow past a symmetric aerofoil: experiments and computations, J. FLUID MECH., Vol. 591.

(26) T.T. Lim & S.S. Lim (2008). Modified expression for critical Reynolds number in eccentric Taylor-Couette flow. AIAA JOURNAL. Vol. 46.

(27) Y.D. Cui, T.T. Lim & H.M. Tsai (2008). Effects of Forebody Slot Blowing on Vortex Breakdown and Load over a Delta Wing., AIAA JOURNAL. Vol. 46.

(28) Lopez, Cui, Marques & Lim (2008).  Quenching of vortex breakdown oscillations via harmonic modulation. J. FLUID MECH., Vol. 599.

(29) T. T. Lim, K.B. Lua & K. Thet (2008). Does Kutta lift exist on a vortex ring in a uniform cross flow ?  PHYS FLUIDS, Vol. 20

(30) Ng, Luo, Lim & Ho (2008). On the relation between centrifugal force and radial pressure gradient in flow inside curved and S-shaped duct. PHYS FLUIDS, Vol. 20.

(31) K.B. Lua, T.T. Lim & K.S. Yeo (2008). Aerodynamic forces and flow fields of a two-dimensional hovering wing. EXP. FLUIDS, Vol. 45.

 (32) Lim, Teo, Lua and Yeo (2009). On the prolong attachment of leading edge vortices on flapping wings  MODERN PHYS LETTER B, Vol. 23.

(33) Cui, Lopez, Lim, and Marques (2009). Harmonically forced enclosed swirling flow. PHYS FLUIDS Vol. 21.

(34) D. Adhikari and T. T. Lim (2009). The impact of a vortex ring on a porous screen. FLUID DYNAMIC RESEARCH (Accepted).

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Video Gallery
(All video images are subject to copyright)

☞ FLAPPING WINGS

Flapping wings (click to view)   

See also http://serve.me.nus.edu.sg/mav/

 

Heaving airfoil in a freestream (click to view)   

☞ ELLIPTIC JET IN CROSS FLOW

 
 E.J.I.C.F. (click to view) 



 

☞ CO-FLOWING JETS AND WAKES

Eddies in Captivity (click to view)

(Producers: A.E. Perry and T. T. Lim)
A clip of 20-minute sound color movie showing the eddying motion in coflowing jets and wakes.

 
Co-flowing jet (click to view) 






Naturally occurring positively buoyant jet (click to view) 



 


☞ VORTEX RINGS
 

                 Motion of an Elliptic Vortex Ring  (click to view)  
 

Head-on Collision of Two Vortex Rings

(a) Re =1000 (click to view):  NATURE, Vol. 357

(b) Re =1573 (click to view):  NATURE, Vol. 357       

   


Leapfrogging of Vortex Rings (click to view)

 

☞ Oblique Collision of Two Vortex Rings

 
Front View (click to view)

 


Top View (click to view)
 

☞  Vortex Ring/Inclined Wall Interaction


Front View (click to view)
 




☞ FLOW INSTABILITY
                                  

Vortex_Induced_Instability (click to view)  

 

Oscillation of Vortex Breakdown (Laser Cross Section) (click to view)  

 Oscillation of Vortex Breakdown (food dye) (click to view)  
 

☞ Turbulent Spot

 
Turbulent Spot (click to view)  
 


☞ Hairpin Vortices


Hairpin Vortices (click to view)  

     


Hairpin Vortices (front View) (click to view)  

 

Equipment (with A.E.Perry and R.M. Kelso) 
               

Flying Hot-wire system (click to view)

 

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Flow Gallery
(All flow images are subject to copyright)

Harmonically forced enclosed swirling flow
(Cui, Lopez, Lim and Marques, Phys Fluids.,Vol 21)


 

Quenching of Vortex Breakdown Oscillation
(Lopez, Cui, Marques and Lim, J. Fluid Mech., Vol 599)


 



Life Cycle of  Vortex Breakdown Bubbles
 (Lim, Cui and Lopez)


Bubble-Type Vortex Breakdowns in an Enclosed Cylinder
(Lim & Cui: Phys Fluids, Vol. 17)

A Spiral-Type Vortex Breakdown in an Enclosed Cylinder
(Lim & Cui: Phys. Fluids, Vol 17)


 Vortex Breakdown over a Delta Wing

 

Control of Vortex Breakdown over a Delta Wing
(Cui, Lim & Tsai: AIAA Journal Vol 45)
        


Multiple-exposed pictures of the motion of a SINGLE vortex ring in a cross flow
(vortex ring is ejected few seconds AFTER the cross flow is initiated)
(Lim, Lua & Thet: Phys. Fluids, Vol 20)





Multiple-exposed pictures of the motion of a SINGLE vortex ring in a cross flow
(vortex ring is ejected few seconds BEFORE the cross flow is initiated)
(Lim, Lua & Thet: Phys. Fluids, Vol 20)



Co-axial Vortex Rings in Quiescent Fluid

    

 

Co-axial Vortex Rings Ejected through Cross Stream Boundary Layer

 

An Elliptic Jet in Cross Flow (E.J.I.C.F.)
(New, Lim & Luo: J. Fluid Mech. Vol. 494)

 

E.J.I.C.F: Cross-section Normal to Jet Trajectory
(New, Lim & Luo: J. Fluid Mech. Vol. 494)

 E.J.I.C.F: Cross-section Normal to Cross Flow
(New, Lim & Luo: J. Fluid Mech. Vol. 494)

A Round Jet in a Cross Flow 
(Kelso, Lim & Perry: JFM, Vol. 306)

 

 A Round Jet in Cross Flow: Near Field
(Lim, New & Luo: Phys Fluids, Vol. 13)

 A Round Jet in Cross Flow: LIF Image
(Lim, New & Luo: Phys Fluids, Vol. 13)

A Free Jet: Vortex Tripling

  

High Angle of Attack Aerodynamics
(Luo, Lim, Lua & others..... AIAA J, Vol. 36)

 

Accelerated Flow Past A NACA 0015 Aerofoil 
(Flow Visualization)
(a=30o, Re=5000, a=0.031m/s2)


Accelerated Flow Past A NACA 0015 Aerofoil 
Streamline Pattern (DPIV)

 

Flow Field of an Oscillating Elliptic Wing (DPIV)
(Chng, Lim, et al. 15 AFMC Re=1000, k=0.5)

 

Vorticity Field of An Oscillating Elliptic Wing (PIV)
(Chng, Lim, et al. 15 AFMC Re=1000, k=0.5)




On the Prolong Attachment of LEV on Flapping Wing
(Lim, Teo, Lua and Yeo, Mod Phys Letter B)


 

Taylor-Couette Flow

 

Taylor-Couette Flow
(Lim, Chew & Xiao: Phys Fluids, Vol. 10, no:12)

 

Breakdown of an Inclined Vortex Ring
(T. T. Lim : Phys Fluids, Vol. 10, no:7)

 
 

 Head-on Collision of Vortex Rings (Re=1000)
(Lim & Nickels: Nature, Vol. 357)

 

 Head-on Collision of Vortex Rings (Higher Re)
(Lim & Nickels: Nature, Vol. 357)



 Head-on Collision of Vortex Rings (Re < 1000)
       
 

Not So Perfect Head-on Collision of Vortex Rings


      Leapfrogging Between Two Vortex Rings 
    (T. T. Lim: Phys Fluids, Vol. 9)

     

    Positively Buoyant Jet: Cigarette Smoke
    (Perry & Lim: JFM, Vol. 88)

     

Positively Buoyant Jet: Chimney smoke
(Perry & Lim: JFM, Vol. 88)

 

Positively Buoyant Jet: Laboratory produced
(Perry & Lim: JFM, Vol. 88)

 

Flow past a Circular Cylinder:: Karman Vortex Street
(Perry, Chong & Lim: JFM, Vol. 116)

 

Flow past a Perforated Plate (Plate porosity (b) = 0.365)

 

Flow past a Perforated Plate (Re=147)

 

Vortex Ring
(Lim & Nickels: Fluid Vortices)

 

Negatively Buoyant Wake
( Perry & Lim: JFM, Vol. 88)

   

Interaction of Two Vortex Rings at an Angle
(T. T. Lim: Expt in Fluids, Vol. 7)

 

A Vortex Ring Interacting With an Inclined Wall
(T. T. Lim: Expt in Fluids, Vol. 7)

     

    Hairpin Vortices
    (Perry, Lim & Teh: JFM, Vol. 104)

     
     

    Laser Cross Section of Hairpin Vortices
    (Perry, Lim & Teh: JFM, Vol. 104)

     

    A Turbulent Spot
    (Perry, Lim & Teh: JFM, Vol. 104)

     
    Water Tunnel Facility

Trisonic Wind Tunnel

Test-section: 1.2m x 1.2m, Mach No: 4 (max)

A joint project between NUS and DSO National Laboratories

All video and flow images are subject to copyright

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Quotations

 

"Be nice to people on your way up because you meet  them on your  way down"
 		 Jimmy Durante
"Minds are like parachutes. They only function when they are open"
 		 Sir James Dewar
"Truth is what stands the test of experience" 
 		 Albert Einstein
"Well done is better than well said"
 		 Benjamin Franklin
"You cannot create experience. You must undergo it"
 		  Albert Camus  
"Be modest! It is the kind of pride least likely to offend"
 		 Jules Renard
"Science is not dictated by majority votes"   
 		 Anonymous
"The objective of basic research is to learn how the world works"
 		 John S. Rigden

"...it is the nature of great research that one cannot predict what basic new insights about the workings of nature will emerge, nor can one dream of what practical applications will follow." 
 

  John S. Rigden
"Science is an international enterprise.........there is no German science, no Asian Science, no Hindu Science"  
 		 John S. Rigden
"Happiness depends on ourselves"
 		 Aristotle
"All I can say about life is, oh God, enjoy it!
 		 Bob Newhart

Updated in 2nd April, 2009.        

Created on 1st August, 2001.