Courses » Spray Theory

Spray Theory

The goal of this course is to provide an overview of physics of liquid atomization, spray formation and propagation. The course will introduce the student to the theoretical models pertaining to jet breakup and drop formation. The application of multiphase models for studying spray transport will also be discussed. Finally, the course will present an overview of the design aspects as they pertain to spray nozzle and atomizers and discuss potential applications in combustion systems.Theoretical modeling of drop formation and atomization: Various regimes of jet breakup will be discussed with relevance to the non-dimensional parameter space. This section will discuss linear instability as well as nonlinear stability based theoretical models for drop formation in both cylindrical jet and annular and planar sheet geometries will be delineated. The course will discuss experimental evidence in support of such theoretical models as proof of validation. Finally, theoretical models of “prompt” atomization will be presented.Drop size distribution models: We will consider a stochastic description of the spray formation and propagation process while paying attention to the physical origins of such distributions. The various existing models for drop size distribution will be discussed. The coupling of these models into a multiphase transport framework for studying spray propagation will be presented. Finally, the various experimental techniques that are employed to interrogate sprays will also be presented.
Spray applications: The final section of the course will discuss various applications of sprays including spray combustion and spray drying. A general overview of the physical processes underlying each application will be presented and an overview of the design process for each application will be discussed.

INTENDED AUDIENCE: Both UG and PG students can take.

1. Undergraduate fluid mechanics.
2. Undergraduate differential

DRDO, Defence, Spray drying users such as pharma, consumer product manufacturers such as Unilever, Proctor and Gamble, Patanjali etc., Aerospace industries, Agrotech for pesticide application etc.

421 students have enrolled already!!


Dr.Mahesh V Panchagnula
Professor of Applied Mechanics
Indian Institute of Technology, Madras

B.S. - Mechanical Engineering, Indian Institute of Technology, 1992
M.S. - Mechanical Engineering, Purdue University, 1994
Ph.D.- Mechanical Engineering,Purdue University, 1998


Week 1: Introduction to sprays and atomization
Week 2: Drop size and velocity distributions
Week 3&4: Atomizers and their designs
Week 5&6: Atomization theory
Week 7&8: Spray theory
Week 9: Practical aspects of atomizer fabrication and manufacturing
Week 10&11: Multiphase flow models of sprays
Week 12: Spray evaporation and combustion 


There is no required text for this course. Course material will come from
available references (PowerPoint presentations) and technical papers.
However, two books of interest are
1. Atomization and Sprays, by A.H. Lefebvre (Hemisphere: New York, 1989.
ISBN 0-89116-603-3) and
2. Liquid Atomization, by L. Bayvel and Z. Orzechowski (Taylor and Francis:
Washington DC, 1993. ISBN 0-89116-959-8).
Lefebvre’s book is superior in providing experimentally based correlations for
predicting nozzle performance and in coverage of combustion related,
specifically gas turbine, sprays.
Bayvel and Orzechowski’s book is superior in coverage of fundamental aspects
of liquid breakup, coverage of transient sprays, such as those found in IC
engines, and coverage of non-combustion sprays, such as agricultural
applications and spray drying.
  • The exam is optional for a fee.
  • Date of Exam: April 28th 2019 (Sunday).
  • Time of Exam: Morning session 9am to 2 noon; Afternoon session: 2pm to 5pm
  • Registration url: Announcements will be made when the registration form is open for registrations.
  • The online registration form has to be filled and the certification exam fee needs to be paid. More details will be made available when the exam registration form is published.

  • Final score will be calculated as : 25% assignment score + 75% final exam score
  • 25% assignment score is calculated as 25% of average of  Best 8 out of 12 assignments
  • E-Certificate will be given to those who register and write the exam and score greater than or equal to 40% final score. Certificate will have your name, photograph and the score in the final exam with the breakup.It will have the logos of NPTEL and IIT Madras. It will be e-verifiable at nptel.ac.in/noc.