Snow guard may not actually be a snow guard

[anotero]

That's not really what's happening, I reference only the effect in a poor attempt to communicate a thought.

I'm an aero engineer, so I take terms like laminar flow at face value.

 

[GroceryGTIer]

They call it a snow guard but it’s basically a pre filter.

It’s a friggen snow screen!

 

[Carlosfandang0]

It’s a friggen snow screen!

Yes it friggin is!

 

[dosjockey]

I'm an aero engineer, so I take terms like laminar flow at face value.

Then examine what happens as the cold air is pulled into coherent flow around that object set against the filter element.

The cooling effect in that system is most similar to the cooling effect encountered by placing the disruptive object in a laminar flow pattern at the same temperature.

 

[GroceryGTIer]

Then examine what happens as the cold air is pulled into coherent flow around that object set against the filter element.

The cooling effect in that system is most similar to the cooling effect encountered by placing the disruptive object in a laminar flow pattern at the same temperature.

I want to know who decided to call it a snow screen... it obviously looks nothing like a screen.

 

[GTIfan99]

They call it a snow guard but it’s basically a pre filter.

So VW doesn't think hot climate countries deserve a pre filter? How does that make sense?

 

[dosjockey]

So VW doesn't think hot climate countries deserve a pre filter? How does that make sense?

It wouldn't really serve much of a purpose. Even in extremely dusty environments, you'd still be opening the airbox to get to it.

I don't think this guard/filter/screen is doing much more than catching buildup of snow and ice that's pushed through the body gap and letting the cold air around it until the engine heats up. Wouldn't want it damaging the filter and buggering the MAFS.

...but, then again, I've had plenty of cars with intakes in that location and never had an issue in cold climates of any humidity or reasonable pressure value.

Maybe Anotero can expand.

 

[anotero]

Then examine what happens as the cold air is pulled into coherent flow around that object set against the filter element.

The cooling effect in that system is most similar to the cooling effect encountered by placing the disruptive object in a laminar flow pattern at the same temperature.

First you say it's not actually laminar (why would it be), then you tell me to examine the flow through that screen. Okay, do you want me to set up the grid or you'll do it?

 

[anotero]

It wouldn't really serve much of a purpose. Even in extremely dusty environments, you'd still be opening the airbox to get to it.

I don't think this guard/filter/screen is doing much more than catching buildup of snow and ice that's pushed through the body gap and letting the cold air around it until the engine heats up. Wouldn't want it damaging the filter and buggering the MAFS.

...but, then again, I've had plenty of cars with intakes in that location and never had an issue in cold climates of any humidity or reasonable pressure value.

Maybe Anotero can expand.

The mk7 doesn't have a MAF sensor, btw.

 

[dosjockey]

First you say it's not actually laminar (why would it be), then you tell me to examine the flow through that screen. Okay, do you want me to set up the grid or you'll do it?

You can set up whatever you like, or come up with a simpler way to explain why the snow is going to stay caked and frozen on that filter in a hot engine bay.

Either way, the cooling result is the same, and the flow directly behind that filter is necessarily coherent. That's where the poor example came from.

I said "effectively" for a reason, and stated that it was a poor attempt at an example, and then even suggested you could expand on a point. I'm not going to argue. I already conceded.

I just got over Rocky Mountain spotted fever, and I'm having trouble making connections that make sense. Every now and again, I'm going to screw something up.

All I can do is admit when it happens, and I've already done that.

 

[GTIfan99]

It wouldn't really serve much of a purpose. Even in extremely dusty environments, you'd still be opening the airbox to get to it.

I don't think this guard/filter/screen is doing much more than catching buildup of snow and ice that's pushed through the body gap and letting the cold air around it until the engine heats up. Wouldn't want it damaging the filter and buggering the MAFS.

...but, then again, I've had plenty of cars with intakes in that location and never had an issue in cold climates of any humidity or reasonable pressure value.

Maybe Anotero can expand.

I agree with you, I was challenging the logic that it's a prefilter. It only installed in cold weather climates. Being a prefilter makes no sense because VW doesn't install it in all regions and they literally call it a snow guard.

I don't see why people keep arguing this. If it had another purpose, all regions would get it from the factory.

 

[anotero]

You can set up whatever you like, or come up with a simpler way to explain why the snow is going to stay caked and frozen on that filter in a hot engine bay.

Either way, the cooling result is the same, and the flow directly behind that filter is necessarily coherent. That's where the poor example came from.

I said "effectively" for a reason, and stated that it was a poor attempt at an example, and then even suggested you could expand on a point. I'm not going to argue. I already conceded.

I just got over Rocky Mountain spotted fever, and I'm having trouble making connections that make sense. Every now and again, I'm going to screw something up.

All I can do is admit when it happens, and I've already done that.

When you say coherent, are you referring to a specific property of turbulent flow?

 

[DiscusInferno]

VW offers a "Cold Weather Filter" which has a piece of foam glued to the bottom of the cellulose filter media (and has offered them for at least 20 years now)

That is for snow, to prevent it from soaking the cellulose filter media reducing its effectiveness

 

[GroceryGTIer]

VW offers a "Cold Weather Filter" which has a piece of foam glued to the bottom of the cellulose filter media (and has offered them for at least 20 years now)

That is for snow, to prevent it from soaking the cellulose filter media reducing its effectiveness

That seems like it would be a big restriction

 

[DiscusInferno]

That seems like it would be a big restriction

If you care about filter flow but not filtering efficiency, then put a K&N in and clean it too frequently.