Oblique Shock Calculator

The fluid flow parameters of an oblique shock wave can be calculated using this oblique shock calculator. When military aircraft or spacecraft travel faster than the speed of sound, they generate a shock wave. Calculating the desired fluid flow qualities is used to design aircraft air intakes. For military jets' air-breathing engines to work properly, air must enter at subsonic speeds.

This is accomplished by inserting wedge-shaped particles into the airflow to compress it before it enters the combustion chamber. Some aircraft have axially adjustable intake cones, while others use inlet ramps for the same reason.

Lockheed F-104, Mikoyan Gurevich MiG-21, and Dassault Mirage 2000 are the three most prevalent aircraft with intake cones. Some planes, such as the Concorde, the Lockheed Martin F22, and the Mikoyan Gurevich MiG-25, manage airflow with an entrance ramp rather than a cone. Due to the creation of shock waves, air travelling through these diffusers slows down and enters the engine at a slower speed at supersonic speeds.

In addition to the beneficial benefits of a shock wave, there are also unfavourable impacts, like sonic booms and high-pressure wavefronts in a blast wave resulting from an explosion, which can result in human deaths. To do so, you'll need to know what a shock wave is and what oblique shock relationships are. Continue reading to learn how to use this oblique shock calculator to calculate fluid flow parameters.

What is a Shock Wave?

A shock wave is a sudden shift in fluid pressure, density and temperature caused by an abrupt discontinuity. It's created whenever a wavefront travels at supersonic speeds and builds up a lot of pressure. Supersonic aircraft, lightning strikes and explosions all produce this high-pressure wave, which travels faster than the local speed of sound and is perceived as a loud crack or whip.

According to studies, a shock wave has a thickness of roughly 200 nm, hence it can be considered a line or plane. Past this line, the fluid's parameters - pressure, density, temperature, and velocity - dramatically changed. To produce ideal post-shock circumstances, different geometries of an aircraft are frequently used to drive these shocks. The following are the two most prevalent types of shock waves:

  1. Normal shock wave
  2. Oblique shock wave

An oblique shock wave is one that deviates at an angle from the local flow, whereas a normal shock wave is one that is parallel to the local flow.

What is the definition of an oblique shock wave?

The oblique shock wave is a shock wave produced by a supersonic flow that is angled to the local fluid flow. This process causes a drop in stagnation pressure and an increase in the system's entropy. It has both positive and negative consequences.

What is the definition of a normal shock wave?

The normal shock wave is formed when the produced shock wave is perpendicular to the local fluid flow direction. The shock wave is thought to be a very tiny line within which the flow velocity and downstream Mach number both fall.

For an oblique shock wave, how do I determine the pressure ratio?

To calculate the pressure ratio, perform the following steps:

  • Step 1: Subtract the sine of the wave angle from the upstream Mach number.
  • Step 2: In the preceding step, find the square of the product.
  • Step 3: Subtract one from the square to get the answer.
  • Step 4: Calculate the specific heat ratio by multiplying the number by two.
  • Step 5: The pressure ratio is calculated by multiplying the product by the sum of the specific heat ratio and 1.

For an oblique shock wave, how can I determine the density ratio?

The density ratio is calculated as follows:

  • Step 1: Multiply the sine of the wave angle from the upstream Mach number.
  • Step 2: In the preceding step, find the square of the product.
  • Step 3: To get the numerator, divide the square by the sum of the specific heat ratio and 1.
  • Step 4: To get the specific heat ratio, subtract one from it.
  • Step 5: Multiply the difference by the square you got in step 2 to get the answer.
  • Step 6: To get the denominator, add by 2.
  • Step 7: To get the density ratio, divide the numerator from step 3 by the denominator from step 6.

Become familiar with plenty of similar concepts of physics along with well designed calculator tools complementing the concept on Physicscalculatorpro.com a trusted reliable portal for all your needs.

FAQs on Oblique Shock Calculator

1. What are the properties of an oblique Shockwave?

A shock wave that is angled with respect to the incident upstream flow direction, unlike a typical shock, is called an oblique shock wave. It happens when a supersonic flow hits a corner and compresses. After the shock wave, the upstream streamlines deflect equally.

2. What's the difference between regular shock waves and oblique shock waves?

The normal shock is at a 90-degree angle to the incoming flow, and the flow behind it is always subsonic, resulting in a substantial total pressure loss, whereas the oblique shock is at an angle to the incoming flow, and only the normal and tangential components of flow velocity are unchanged.

3. What is the nature of the flow's Mach number after a regular shock wave?

During a shock wave, the flow's Mach number and speed both fall. A normal shock occurs when the shock wave is perpendicular to the flow direction.

4. Is it true that Mach waves are isentropic?

Each Mach wave is isentropic, the entire expansion zone is also isentropic, allowing isentropic relations to be applied throughout the entire region. We shall see an increase in flow Mach number, a decrease in pressure, a fall in density, and a decrease in temperature over an expanding zone.

5. What's the difference between a shock wave and a Mach?

A Mach wave is created as the wedge angle approaches an infinitely tiny limit. On the other hand, shock waves are created when the wedge angle is set to a limited value.