Shipping Estimate
USA
- USA
- CAN
- USA
- CAN
Ships within 48 hours · Estimated delivery Jul 8 - Jul 13
Promo Codes Available:
For Your Every Summer RSVP, with Code: SUMMER15
Description
On the interactions of sound waves and vorticesThe effects of vortical mean flows on the propagation of acoustic waves are numerous, from simple convection effects to instabilities in the acoustic phenomena, including absorption, reflection and refraction effects. Therefore, the role of vorticity in acoustic propagation besides noise generation has been a subject of controversial discussions since the foundation of aeroacoustics. In this work, a theoretical study with subsequent industrial
The effects of vortical mean flows on the propagation of acoustic waves are numerous, from simple convection effects to instabilities in the acoustic phenomena, including absorption, reflection and refraction effects. Therefore, the role of vorticity in acoustic propagation besides noise generation has been a subject of controversial discussions since the foundation of aeroacoustics. In this work, a theoretical study with subsequent industrial applications has been performed, concerning the derivation of a family of scalar operators for aeroacoustics based in total enthalpy terms and including mean vorticity effects in the propagation.
Shipping Notes
- Free Standard Shipping on $100+ Orders to the USA.
- Except Preorder products are shipped in 48 hours.
- Delivery to the USA:
- Standard Shipping : 3-10 business days
- If time is of the essence, please consider selecting expedited delivery for faster service.
Exchange/Return Notes
- We offer a 30-day return/exchange service after receiving.
- Final sale items are not eligible for returns or exchanges.
- To process your return/exchange, please contact us at [email protected]
- Please click here for more details>>> Return & Exchange Policy
4.8 ★★★★★
Based on 1007 reviews
Sort
Product Reviews
★★★★★ 5
Very Comfortable
Great! I was a little concerned when it came so tightly shrink wrapped, but a day or two later and it’s in great shape. It’s actually pretty comfortable, good angle. It’s a good width and pretty long to accommodate all body types. I like it can be two heights. My adult kids said it felt like memory foam. I can add my own pillow too to further adjust to my liking. I occasionally get bad heartburn or sick where I need to sleep sitting up. This helps me do that in bed. I tried using it every night at first because I usually sleep with two large stacked pillows, but I’m a side sleeper and it eventually hurt my neck. So, not great if you sleep on your side. I also just lay a pillow case across it to keep clean. You can unzip and take off the cover for cleaning, but I almost never get stuff like that back on right. I got the dark gray cover and I like the soft feel. I’m glad I got it.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on March 16, 2026
★★★★★ 5
Lifesaver while recovering from rotator cuff surgery
This pillow was a lifesaver, it’s sturdy yet comfortable and can be used many different ways! Great price and size too! I like that when I opened it, there was no smell! If you’re looking for a wedge pillow, this one will do the job!!
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on March 10, 2026
★★★★★ 4
It is a great wedge pillow, but takes time to get used to sleeping on your back
Color: Dark Grey & White, Size: Adjustable 9&12 Inch + 1 Head Pillow
I bought this for post-surgery, I had to sleep on my back. Nearly impossible as a lifelong side sleeper. It is memory foam, and it does seem to run hot. But after a couple of weeks, I'm adjusting to it. Back sleeping is best for saving your face from AM wrinkles and mascara smears all over pillows. (Yes I know, I should take off mascara before bed, but....). Now that I've adjusted to sleeping with it, it stays on my bed and I wake up without the creases on my face and neck! So if you are buying pre-surgery, buy in advance to adjust to a new style of sleeping! I'm keeping it!
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on November 7, 2025
★★★★★ 5
Its worth the purchase!
Color: Black, Size: Adjustable 9&12 Inch + 1 Head Pillow
Bought this pillow because Im dealing with both GERD and neck pain so I decided to order this and hope for the best thats being said Im so glad I did because its helped me a lot with both issues.
Some extra comments: Its a little firm but not in a bad way and the head rest is comfy but I do wish I could bring it down lower.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on June 3, 2026
★★★★★ 3
Misleading: Pillow Itself Has Only TWO Configurations!! >:(
Color: Black, Size: Adjustable 9&12 Inch + 1 Head Pillow
I was sold on the 10-Option bit until I realized there are only 2 choices as far as flooping and flopping the pillow itself. It is 2 triangles, a large one and a small one. The large triangle IS THE SAME ANGLE ON EACH END. The small triangle IS ATTACHED TO THE CENTER OF THE LARGE TRIANGLE. That means no matter how you move the pillow itself, you're getting the EXACT SAME THING. Where YOU come in is where all these infinity "versatility" options are - whether you put it upright or whether you put it flat. That's it. All this I can read in bed! I can play on my laptop! I can watch TV! Yeah that's upright. Option 1. And all this I can put it under my legs! I can use it as a normal pillow as well! That's flat. Option 2. There is absolutely nothing special or different about this thing except the stupid pocket. Had they not made the triangle the same angles on the end, had they made a steep angle and a low angle and that center pillow detachable but still velcro - THEN there would have been more elevation options. But this, I was highly disappointed. It's like saying, My bed has 360 options! (because I can lay 360 different degrees around the bed) AND 360 MORE BECAUSE GUESS WHAT! I CAN LAY ON MY STOMACH 360 DIFFERENT DEGREES around the bed! Oh! And on my side 360 degree different ways! Wait I have a left and a right side - the OTHER side I can lay on it around the bed 360 different degrees as well! And sitting cross-legged on the bed 360 different degree directions as well! So. No. It's a firm memory foam pillow. You lay upright or lay down or you put it under your legs or on your lap. It changes 2 ways and you make it work 4 ways. That's it. Yes it smells but not too bad, not foul, just persistently. Like a light chemical smell but it didn't aggravate me (I get scent, etc. migraines). It self-inflated pretty fast. But as you can tell, I was not impressed with it in reality. :(
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on May 3, 2026