Recent content by DadoNoah

Certainly, but I meant more like, do your shear rate calculations yield similar force values to my Poiseuille calculations at 0.4 cc/sec and 0.25 cc/sec?

Yeah, I think you're right-- I updated my formula to cancel out the P0 term per your advice, and it gives me about 79 N for a 1 cm2 piston. However, I should note that 0.5 cc/sec is the absolute maximum flow rate I foresee needing. Plugging 0.4 cc/sec into my Poiseuille-based formula gives me a...

Yeah, I see what you mean about the pressure drop in the needle. That 1/rN4 term really blows up. But could you elaborate about atmospheric pressure balancing out? Am I missing an additional P0 term acting on the plunger? The viscosity of the resin is around ~930 cP, or ~0.93 Pa*s. I'm still...

I couldn't agree more, and I thank you for making me double-check! I feel much more confident now picking out a syringe and taking the plunge *ba-dum tiss*

Thanks for the reply Arjan! So if I'm understanding correctly, my current solution will underestimate pressure PB, and by extension will underestimate force F? If it helps, I'll be using this setup to apply very small quantities of resin at a time, so my target flow rate Q will likely be very...

I'm currently working on a precise glue/resin dispenser, and I'm trying to derive an equation for the force one must exert on a syringe plunger as a function of the desired flow rate Q, and also accounting for the fluid viscosity and the syringe barrel and needle geometry. I've attached a scan...