Design of impeller blades of an axial pump
Design of impeller blades of an axial pump
(OP)
Hi,
Does anybody have any great books or references on the design of the blades of an axial pump, and their profile?
So far I've only been able to find books and articles mentioning that the blades are airfoil formed, but I haven't found any rule of thumb or handbook on the actual profile selection.
Hope my question makes sense, and thanks in advance!
Does anybody have any great books or references on the design of the blades of an axial pump, and their profile?
So far I've only been able to find books and articles mentioning that the blades are airfoil formed, but I haven't found any rule of thumb or handbook on the actual profile selection.
Hope my question makes sense, and thanks in advance!





RE: Design of impeller blades of an axial pump
Given that an axial flow pump impeller is likely to be relatively small in diameter(lets say a couple meters at the most even in a large unit) then it would be unlikely that a single airfoil would be appropriate due to the change in chord, pitch and linear velocity over the length of the blade.
The "aerodynamics" of a propeller in an axial flow pump is obviously heavily impacted by the viscosity of the fluid and as such the best such airfoil section would be very different to a aircraft propeller or wing.
Regards
Ashtree
"Any water can be made potable if you filter it through enough money"
RE: Design of impeller blades of an axial pump
It is a capital mistake to theorise before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts. (Sherlock Holmes - A Scandal in Bohemia.)
RE: Design of impeller blades of an axial pump
It's for a very small blood pump, about 25mm in diameter. And we estimate about 4000-6000 rpm, so the Reynolds number along the length of the blades are both laminar, turbulent and transitional. The current pumps(LVAD's) have what seems to be a well thought out design, in order to avoid blood damage.
e.g. [img https://image.slidesharecdn.com/vadjosesoto1112f-1...]
That's not the aim of the project at this point though. We want to see if it's possible with a more typical design. We've been looking at NACA 4-series profiles so far, since we can easily get the lift and drag coeffecients for these profiles using XFOIL. And then just using simple 2d velocity diagram to decide the angles. Though I've been reading that due to our hub/tip ratio, we need to look into 3d flow over the blades.
Thanks
RE: Design of impeller blades of an axial pump
Yes, the profile varies greatly with radial position.
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P.E. Metallurgy, Plymouth Tube
RE: Design of impeller blades of an axial pump
A few life times back I worked for a manufacturer who designed and manufactured axial flow pumps (true airfoil) with impeller diameters of 4" to 24"- 4,5,6,8,blades depending on pump size and blade tilt, we also had a scale model unit with impeller diameter something below 1", the flowrate was unbelievable for its size, as to the developed I have no idea but would think it only a couple of feet at best.
Rather than such high speed, multi stage might be a better option.
It is a capital mistake to theorise before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts. (Sherlock Holmes - A Scandal in Bohemia.)
RE: Design of impeller blades of an axial pump
Perhaps you don't want a mixed flow design.
Walt
RE: Design of impeller blades of an axial pump
We estimate a flow rate of about 6 L/min, and a head of about 30 mmHg. I'll have to look into multistage, though I think size will be a problem. The Mixed flow pumps look interesting!
RE: Design of impeller blades of an axial pump
It is a capital mistake to theorise before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts. (Sherlock Holmes - A Scandal in Bohemia.)