Speed of sound in vortical flows

In summary, the conversation was about determining the speed of sound in a linear gaseous flow and wanting to know more about the speed of sound in a vortical flow. The recommended resources were "Wave Equation for Sound in Fluids with Vorticity" and using Clebsch potentials and an action principle to derive a closed system of gauge invariant equations for sound superposed on a general background flow. However, it was also mentioned that in an ideal gas, the speed of sound can be determined using a simpler equation.
  • #1
zak8000
74
0
hi there

I am currently working with linear flows and using a ultrasonic setup to determine the speed of sound in a linear gaseous flow. But I would like to know more about the speed of sound in a vortical flow. Unfortunately I haven't been able to find any good book with regard to my topic and was wandering anyone could offer a good book or paper to get me going

thanks
 
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  • #2
In an ideal gas, the speed of sound is always [itex]a = \sqrt{\gamma R T}[/itex] where [itex]\gamma[/itex] is the ratio of specific heats, [itex]R[/itex] is the specific gas constant and [itex]T[/itex] is the static temperature. It doesn't matter if it is vortical or quiescent or anything else as long as it is an ideal gas in this case.
 
  • #3
“Wave Equation for Sound in Fluids with Vorticity”

“Abstract
We use Clebsch potentials and an action principle to derive a closed system
of gauge invariant equations for sound superposed on a general background
flow. Our system reduces to the Unruh (1981) and Pierce (1990)
wave equations when the flow is irrotational, or slowly varying. We illustrate
our formalism by applying it to waves propagating in a uniformly rotating
fluid where the sound modes hybridize with inertial waves.”
http://arxiv.org/abs/cond-mat/0106255
 
  • #4
Assuming you have an ideal gas and can treat it as a continuum, there is no need to set up a wave equation and Clebsch potentials (of which I am only vaguely familiar) in order to determine the speed of sound at a given point in a gas.

Of course me being me, now I am on a quest to figure out why the authors required a more complicated formulation like in the linked paper. They didn't really explain when and why you would need that in the paper and I don't have time to dig any further at the moment, but I am quite curious. The authors seem mostly interested in vorticity in superfluids, and I doubt that applies all that well to the OP's question, though I guess it might.
 
  • #5
for your interest in the speed of sound in vortical flows! This is a very interesting and complex topic that has been studied by many scientists and researchers. I would recommend looking into some papers and books by experts in the field such as Prof. William K. George from the University of Illinois at Urbana-Champaign or Prof. Alexander Smits from Princeton University. Some specific papers that may be of interest to you include "Acoustics of vortical flows" by Prof. George and "Sound generation in high-speed turbulent shear flows" by Prof. Smits. These papers can provide a good overview of the current understanding and research in this area. Additionally, looking into journals such as the Journal of Fluid Mechanics or the Journal of Sound and Vibration may also provide valuable information on the subject. I hope this helps and good luck with your research!
 

FAQ: Speed of sound in vortical flows

1. What is the speed of sound in vortical flows?

The speed of sound in vortical flows refers to the speed at which sound waves propagate through a fluid that is undergoing vortical motion, such as swirling or spiraling. It is affected by the properties of the fluid, such as density and viscosity, as well as the strength and structure of the vortices.

2. How does the speed of sound in vortical flows differ from the speed of sound in regular flows?

The speed of sound in vortical flows is typically lower than the speed of sound in regular flows. This is because the swirling motion of the fluid creates areas of high and low pressure, which affects the speed at which sound waves can travel through the medium.

3. What factors can affect the speed of sound in vortical flows?

The speed of sound in vortical flows can be affected by the properties of the fluid, such as its density and viscosity, as well as the strength and structure of the vortices. Additionally, the temperature and pressure of the fluid can also impact the speed of sound.

4. How is the speed of sound in vortical flows measured?

The speed of sound in vortical flows can be measured using various techniques, such as laser Doppler anemometry, acoustic Doppler velocimetry, or hot-wire anemometry. These methods involve measuring the velocity of the fluid and the corresponding changes in pressure, which can then be used to calculate the speed of sound.

5. What are some real-world applications of understanding the speed of sound in vortical flows?

Understanding the speed of sound in vortical flows is important in various fields, such as aerospace engineering, acoustics, and meteorology. It can help in the design and optimization of aircraft and other vehicles, as well as in predicting and controlling noise pollution. It is also relevant in understanding weather patterns and the formation of natural phenomena like tornadoes and hurricanes.

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