Background

Doctor of Philosophy
Department of Aeronautics and Astronautics, Stanford University (2002-2007)

Master of Science
Department of Aeronautics and Astronautics, Stanford University (2001-2002)

Bachelor of Technology
Department of Aerospace Engineering, IIT Madras (1997-2001)
 

Research Interests

Numerical Computing Platforms for Aerodynamics (2007 - )

Currently I plan to work on developing computational routines for flow solutions/shape optimization. Everything developed will be geared towards the next two research topics.

Hypersonic Aero-servo-thermo-elasticity (2007 - )

The hypersonic regime occurs, roughly speaking, when the flight Mach numbers are in excess of 5. At these conditions, the coupling between the aerodynamics, the structures, and the thermal heat transfer is extremely strong.

Moreover, the aerodynamic analysis, by itself, is not straightforward anymore, as the gases under consideration become ionized and dissociated. The density goes through order of magnitude variations across the flow field. Real gas effects become important to consider. In case of re-entry vehicle dynamics, the continuum hypothesis might not hold true as well.

All these make the study of hypersonic vehicles challenging. I'm very interested in the study of hypersonic aerodynamics/aero-servo-thermo-elasticity.

Clean Energy - Windmills ( 2007 - )

Designing optimal airfoils/blade shapes.

Algorithms for Automatic Feedback Control of Aerodynamic Flows (PhD Thesis)

My thesis focuses on deriving algorithmic frameworks for the control of Aerodynamic Phenomena. The application of one such control law to the control of Flutter is discussed in detail. Flutter is an aero-structural instability that arises due to the adverse transfer of energy between the airplane structure and the surrounding fluid.

CFD is now a mature technology and can be used as a design tool in addition to being used as an analysis tool. This is the motivation for much of the research that takes place at the Aerospace Computing Lab at Stanford. We specialize in designing aerodynamic shapes that are optimum for any given purpose. Shape optimization involves finding the shape (2D or 3D) that optimizes a certain performance index. Clearly, any optimum shape will be optimum only at the design point. It has been found that the aerodynamic performance at neighboring operating points is a lot less optimal than the original shapes. What we need to do is to design and develop a feasible way of controlling the flow at any operating point such that the resulting performance is optimal.

In designing control laws, our philosophy has been to develop an algorithmic framework that enables treating a broad class of control problems rather than design control laws for specific isolated cases. This ensures that once a framework is established, extensions to particular problems can be done with very little effort. The framework we develop is problem independent and controller independent. Moreover, it has been shown that this leads to control laws that are feedback based, hence robust.

Publications

2007
			Karthik Palaniappan, "Algorithms for automatic feedback control of aerodynamic flows", PhD Thesis submitted to the Department of Aeronautics and Astronautics and the Committee on Graduate Studies of Stanford University, June 8 2007.
2006
			Karthik Palaniappan, Phil Beran and Antony Jameson, "Optimal control of LCOs in aero-structural systems: Having your (nonlinear) cake and eating it too", 2nd AIAA Multidisciplinary Design Optimization Specialist Conference, AIAA Paper 2006-1621, Newport, Rhode Island, May 2006.
			Karthik Palaniappan, Pradipta Sahu, Juan Alonso and Antony Jameson, "Active flutter control using an adjoint method", 44th AIAA Aerospace Sciences Meeting and Exhibit, AIAA Paper 2006-0844, Reno, Nevada, January 2006.
			Karthik Palaniappan and Antony Jameson, "Feedback control of aerodynamic flows", 44th AIAA Aerospace Sciences Meeting and Exhibit, AIAA Paper 2006-0843, Reno, Nevada, January 2006.
2004
			Karthik Palaniappan and Antony Jameson, "Bodies having minimum pressure drag in supersonic flow: Investigating nonlinear effects", 22nd AIAA Applied Aerodynamics Conference and Exhibit, AIAA Paper 2004-5383, Rhode Island, August 16-19 2004.
			Karthik Palaniappan and Antony Jameson, "An analysis of bodies having minimum pressure drag in supersonic Flow: Exploring the nonlinear domain", International Conference on Computational Fluid Dynamics (ICCFD3), Toronto, Canada, July 12-16 2004.