Ultrasound velocities in h20/propylene glycol mixtures

In summary, the conversation discusses the results of a study on the velocity of ultrasound waves in mixtures of water and propylene glycol. The data shows a bell curve with the peak velocity at a 50-50 mixture, but it is noted that the behavior is not surprising due to the non-linear relationship between density and other properties. The units on the y-axis are mm/μs and the goal of the study is to design an ultrasound camera for use in cold weather pipe corrosion measurements.
  • #1
gosatomnadzor
4
0
I started with a 100% water sample, and measured the speed of ultrasound using 1MHz transducer, and in 10% increments added propylene glycol to the sample fixture until I reached 100% propylene glycol.

Curiously, the velocity of ultrasound waves when plotted against % propylene glycol resembled a bell curve with the peak velocity at a mixture of 50% propylene glycol / 50% water mixture. See picture attached for graph. Does anyone have an explanation why the velocity increases until 50-50 mixture, then tails off as % propylene glycol increases?
 

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  • U-S VELOCITY V. PROPGLYC PERCENT.png
    U-S VELOCITY V. PROPGLYC PERCENT.png
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  • #2
gosatomnadzor said:
I started with a 100% water sample, and measured the speed of ultrasound using 1MHz transducer, and in 10% increments added propylene glycol to the sample fixture until I reached 100% propylene glycol.

Curiously, the velocity of ultrasound waves when plotted against % propylene glycol resembled a bell curve with the peak velocity at a mixture of 50% propylene glycol / 50% water mixture. See picture attached for graph. Does anyone have an explanation why the velocity increases until 50-50 mixture, then tails off as % propylene glycol increases?

I don't have an explanation for the specific values but it is not a surprising behavior.
It is known that the density of aqueous solutions is not a linear function of density.
Other properties (including bulk modulus) may have similar non-linear behavior.
So the speed of sound may may have various non-linear dependence on concentration.
By the way, what are the units on your y axis?
The speed in pure water is around 1500 m/s or 1.5 mm/μs.
 
  • #3
Nasu,

thank you for info, y-axis units are mm/μs,
I'll stick the real curve in for your info later, last night I was trying to go from my own recollection of the curve I generated in my lab.

GosAtomNadzor
 
  • #4
Here are the actual results and graph - attached

I appreciate the replies
 

Attachments

  • prop glycol and water u-s velocities.jpg
    prop glycol and water u-s velocities.jpg
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  • #5
Thank you for sharing your data.
The values look OK. If you could measure the density of the solution at these concentrations then you could separate the effect of density variation from changes in elastic properties.
What is the goal of your measurements?
 
  • #6
Nasu,
the goal of our measurements is to design an ultrasound camera acoustic lens set for use in cold weather pipe corrosion non-destructive ultrasound measurements. going from pure water to a mix of h20/propylene glycol changes indexes of refraction for ultrasound lenses as the velocity of ultrasound changes.

thanks
G.A.N
 

1. What is the purpose of studying ultrasound velocities in H2O/propylene glycol mixtures?

The purpose of studying ultrasound velocities in H2O/propylene glycol mixtures is to understand the behavior and properties of these mixtures in various applications, such as in the pharmaceutical and food industries. Ultrasound velocities can provide important information about the structure and interactions of molecules in these mixtures, helping to optimize their use in different processes.

2. What factors can affect ultrasound velocities in H2O/propylene glycol mixtures?

There are several factors that can affect ultrasound velocities in H2O/propylene glycol mixtures, including temperature, concentration of propylene glycol, and pressure. Changes in these factors can alter the density, viscosity, and compressibility of the mixture, which in turn affects the speed of sound.

3. How is the speed of sound measured in H2O/propylene glycol mixtures?

The speed of sound in H2O/propylene glycol mixtures can be measured using ultrasonic techniques, which involve sending high frequency sound waves through the mixture and measuring the time it takes for the waves to travel through it. This information is then used to calculate the speed of sound in the mixture.

4. What are the typical values of ultrasound velocities in H2O/propylene glycol mixtures?

The ultrasound velocities in H2O/propylene glycol mixtures can vary depending on the temperature, concentration, and other factors. However, in general, the speed of sound in these mixtures is lower compared to pure water or propylene glycol. For example, at room temperature, the speed of sound in a 50/50 mixture of H2O and propylene glycol is around 1410 m/s.

5. How do ultrasound velocities in H2O/propylene glycol mixtures relate to other properties of the mixture?

Ultrasound velocities in H2O/propylene glycol mixtures are closely related to other properties such as density, viscosity, and thermal conductivity. Changes in these properties can affect the speed of sound in the mixture, and vice versa. Therefore, studying ultrasound velocities can provide insight into the overall behavior and properties of the mixture.

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