Mediaspace scheduled maintenance: Aug 25, 2026 07:00 - 12:00 AM. During this time, videos will be temporarily unavailable. Check status updates.

Lecture

Convergent Nozzle Behavior

In course

ME-343: Compressible-fluid dynamics

Fluides compressibles, vitesse sonique, ondes de choc, détente. ...

Description

This lecture focuses on the behavior of a convergent nozzle, discussing the impact of varying back pressure on flow characteristics. It explains how changes in back pressure affect flow speed and pressure distribution along the nozzle, leading to different flow regimes. The lecture covers the concept of sonic blockage, where the flow reaches a maximum value and cannot be further increased by reducing back pressure. It also introduces the use of expansion waves to transition from high to low pressure regions. The analysis includes graphical representations of flow parameters at different points along the nozzle, illustrating how flow properties evolve from the reservoir to the nozzle exit. The lecture concludes by hinting at the upcoming study of convergent-divergent nozzles, which present more complex flow phenomena.

This video is available exclusively on Mediaspace for a restricted audience. Please log in to MediaSpace to access it if you have the necessary permissions.

Watch on Mediaspace

Instructor

Flavio Noca

Official source

Related concepts (14)

Pressure

Pressure (symbol: p or P) is the force applied perpendicular to the surface of an object per unit area over which that force is distributed. Gauge pressure (also spelled gage pressure) is the pressure relative to the ambient pressure. Various units are used to express pressure. Some of these derive from a unit of force divided by a unit of area; the SI unit of pressure, the pascal (Pa), for example, is one newton per square metre (N/m2); similarly, the pound-force per square inch (psi, symbol lbf/in2) is the traditional unit of pressure in the imperial and US customary systems.

Fluid dynamics

In physics, physical chemistry and engineering, fluid dynamics is a subdiscipline of fluid mechanics that describes the flow of fluids—liquids and gases. It has several subdisciplines, including aerodynamics (the study of air and other gases in motion) and hydrodynamics (the study of liquids in motion). Fluid dynamics has a wide range of applications, including calculating forces and moments on aircraft, determining the mass flow rate of petroleum through pipelines, predicting weather patterns, understanding nebulae in interstellar space and modelling fission weapon detonation.

Potential flow

In fluid dynamics, potential flow (or ideal flow) describes the velocity field as the gradient of a scalar function: the velocity potential. As a result, a potential flow is characterized by an irrotational velocity field, which is a valid approximation for several applications. The irrotationality of a potential flow is due to the curl of the gradient of a scalar always being equal to zero. In the case of an incompressible flow the velocity potential satisfies Laplace's equation, and potential theory is applicable.

Stokes wave

In fluid dynamics, a Stokes wave is a nonlinear and periodic surface wave on an inviscid fluid layer of constant mean depth. This type of modelling has its origins in the mid 19th century when Sir George Stokes – using a perturbation series approach, now known as the Stokes expansion – obtained approximate solutions for nonlinear wave motion. Stokes's wave theory is of direct practical use for waves on intermediate and deep water. It is used in the design of coastal and offshore structures, in order to determine the wave kinematics (free surface elevation and flow velocities).

Flow measurement

Flow measurement is the quantification of bulk fluid movement. Flow can be measured using devices called flowmeters in various ways. The common types of flowmeters with industrial applications are listed below: Obstruction type (differential pressure or variable area) Inferential (turbine type) Electromagnetic Positive-displacement flowmeters, which accumulate a fixed volume of fluid and then count the number of times the volume is filled to measure flow. Fluid dynamic (vortex shedding) Anemometer Ultrasonic flow meter Mass flow meter (Coriolis force).

Related lectures (31)

Symmetries and Conservation Laws

Covers symmetries and conservation laws in fluid dynamics, emphasizing the importance of maximizing symmetries in ideal fluid systems.

Bernoulli Equation

Explores the Bernoulli equation and its applications in fluid dynamics, including pressure, gravity, and velocity effects.

Fluid Dynamics: Principles and Applications

Provides an overview of fluid dynamics principles, focusing on pressure differences and hydrostatic equilibrium in various fluid systems.

Boundary Layers: Recap and Effects on Drag and Lift

Covers the importance of boundary layers, viscosity effects on drag and lift.

Fluids: Modeling and Simulation