From Wiki –

In fluid dynamics, the Euler equations are a set of partial differential equations governing adiabatic and inviscid flow.

They are named after Leonhard Euler.

In particular, they correspond to the Navier–Stokes equations with zero viscosity and zero thermal conductivity.

The Euler equations can be applied to incompressible and compressible flows.

The incompressible Euler equations consist of Cauchy equations for conservation of mass and balance of momentum, together with the incompressibility condition that the flow velocity is divergence-free.

Historically, only the equations of conservation of mass and balance of momentum were derived by Euler.

However, fluid dynamics literature often refers to the full set of the compressible Euler equations – including the energy equation – as “the compressible Euler equations”

THIS SIMPLY MEANS THAT THE ABOVE EQUATION is mainly used in applications in Aerospace Engineering, AI, Automotive and Chemical Engineering.

TECHNIQUE – One of the old notes of a student of KN Rao mentions about the usage of degree system of astrology and therefore has multiple variations on it that a whole set of course or book can be written on it.

It says that – If the degree of Lagna and Sun or Moon (luminary) is same and Rahu is further in degree from both and connected with 8th house or Mars, the person has great scientific calibre.

In the chart of Leonhard Euler, he has Sun at 4 degree and the Lagna is also rising with the same degree which Rahu being the 8th lord is placed in 10th with exalted Sun and Sun is placed in Dashansh Lagna and next to it is Rahu with Sun getting aspected by Mars from the sign of Scorpio.

Similar variations can be used depending upon the usage of planet so you need to check which planet is ahead of the other and also in special position.