Capacitors are sometimes explained with a water analogy, as a rubber dam across a pipe. This stops DC (continuous flow of water) but AC (to-and-fro ebb and flow motion) passes through.
A Windkessel could be a shunt pipe with a flexible dam, and that's analogous to the flexible pipe, like the artery. Flexible pipes have a shunt capacitance and so they act as filter caps.
I was thinking about all this yesterday and it occured to me that, I suspect, when we put water capacitors in series (i.e. two or more rubber dams across the same pipe), it should also work to reduce the total capacitance, just like electronic capacitors.
If you think about it, the same pressure, if it has to work against two dams in series, will cause a small displacement of rubber, then if there is only one. Two thin rubber dams in series are like one thick one, and that has less capacitance due to being harder to displace. Capacitance is how much the rubber will stretch in the face of a given amount of pressure, thereby accommodating a volume of water.
Two successive dams will never have more capacity because they work to cancel each other. The second dam only stretches to absorb exactly the quantity of water displaced by the first dam; it doesn't provide additional capacity. And due to two dams being harder to stretch, the capacitance (volume pushed per pressure) is reduced.
I think I'm going to add this to my old Electronics StackExchange answer:
Google scholar reports 22,000 papers with Windkessel in them; I've written a few. Pubmed reports over 800 with it in the title.
The concept of the Windkessel is cool. The notion that it hasn't been applied to the heart-aorta system is vexing. I feel like I must be misunderstanding.
As I read it, these physicists came across the notion of windkessel in some medical/physiological literature and realized that this is an understudied physical phenomenon. So I think the claim is less that they’re doing something revolutionary for understanding the circulatory system but rather that they’ve come across something whose underlying physics are a lot less studied than they expected.
This isn't really a new question... every cardiologist was taught the Windkessel model of the cardiovascular system, and it's taught in med school today (I am a med student). We specifically learned it as a RC filter (aortic compliance and vascular resistance) attached to an impulse train (the heartbeats). It makes a great homework problem to think about how the blood pressure waveform changes with calcification.
From the diagram, it looks exactly like a decoupling capacitor in an electronic circuit, for smoothing a voltage.