🎥 Watch: Introducing the Principle of Minimum Pressure Gradient (PMPG)
This short video introduces the physical intuition behind PMPG — a new variational principle we developed that reformulates incompressible flow as a minimization problem. It explains how pressure arises as a constraint force and demonstrates the analogy between a constrained particle and a fluid element. Ideal for engineers and researchers interested in alternative formulations of fluid mechanics.Â
This project introduces the Principle of Minimum Pressure Gradient (PMPG) — a new foundational principle in fluid mechanics we derived from Gauss’ Principle of Least Constraint. Unlike the classical Navier–Stokes approach, which solves for pressure as a coupling variable through Poisson's equation, PMPG reveals that nature minimizes the magnitude of the pressure gradient to satisfy incompressibility.
This reformulation turns fluid simulation into a pure minimization problem, offering a physically grounded alternative to traditional PDE-based solvers.
Pressure acts as a constraint force, enforcing divergence-free velocity fields — much like the normal force keeps a particle on a surface.
PMPG reframes incompressible flow as an optimization problemÂ
The Navier–Stokes equations emerge as first-order optimality conditions from this principle.
The framework is generalizable to non-Newtonian fluids, electromagnetically forced flows, and active systems.
PMPG makes use of the interpretation of pressure in fluid dynamics: it’s the force that enforces incompressibility.
It eliminates the need for pressure–velocity coupling iterations in CFD.
It defines a natural loss function for machine learning models (e.g., Physics-Informed Neural Networks).
It opens new paths for modeling in biofluid dynamics, non-Newtonian flows, and data-driven optimization.
Using PMPG, classical flow problems were solved without using the Navier–Stokes equations, demonstrating both accuracy and insight:
A novel lift theory applicable to any generic shape lacking a sharp trailing edge, without invoking the Kutta condition which is invalid for shapes without sharp edges, unsteady fluid or at high angles of attack.
Predicting the separation angle on a stationary cylinder without explicitly incorporating boundary layer effects!
Analyzing flow over a rotating cylinder within an inviscid framework! a task that previously deemed impossible.
PMPG predicted circulation against RANS simulations for different TE sharpness
PMPG predicted circulation for different shapes
Rotating Cylinder
Stationary Cylinder