What is the temperature? You are aware that, under these conditions, the dynamic viscosity (a physical property of the air) is a unique function of temperature that you can look up on line, right?Angelina21 said:Homework Statement
Considering an airfoil (a flat plate) flying at 100 m/s under sea-level conditions, so the density is 1.225 kg/m3 and the length being 1 m, what is the dynamic viscosity of air? The problem is that I have two variables in one formula, Reynolds number and the viscosity.
Homework Equations
Dynamic viscosity=(density*velocity*length)/Re
The Attempt at a Solution
The temperature according to sea level conditions is 15oC. I'm aware that it's online. But doesn't the viscosity depend on velocity? Or it's always constant, no matter the velocity?Chestermiller said:What is the temperature? You are aware that, under these conditions, the dynamic viscosity (a physical property of the air) is a unique function of temperature that you can look up on line, right?
Like I said, it's a physical property of the air, independent of anything being done to the air.Angelina21 said:The temperature according to sea level conditions is 15oC. I'm aware that it's online. But doesn't the viscosity depend on velocity? Or it's always constant, no matter the velocity?
Dynamic viscosity is a measure of the resistance of a fluid to flow. It is a property of fluids, such as air, that affects how easily they can move and how much force is needed to make them flow.
The dynamic viscosity of air is typically measured in units of Pascal-seconds (Pa·s) or centipoise (cP) using equipment such as viscometers or rheometers. These instruments apply a known force to a fluid and measure the resulting shear rate, from which the dynamic viscosity can be calculated.
At room temperature (around 25 degrees Celsius), the dynamic viscosity of air is approximately 1.8 x 10^-5 Pa·s or 1.8 x 10^-2 cP. However, this value can vary depending on factors such as altitude, humidity, and composition of the air.
The dynamic viscosity of air plays a significant role in how objects move through it. The higher the dynamic viscosity, the more resistance there is to the movement of the object. This can affect the speed, stability, and efficiency of the object's motion.
Yes, the dynamic viscosity of air can change depending on various factors such as temperature, pressure, and composition. For example, as temperature increases, the dynamic viscosity of air decreases, making it easier for objects to move through it. Additionally, different gases have different dynamic viscosities, so changes in the composition of air can also affect its dynamic viscosity.