Advertisement

Springer Nature is making SARS-CoV-2 and COVID-19 research free. View research | View latest news | Sign up for updates

Influence of cavitation on blade characteristics

Abstract

An experimental study of flow around a blade with a modified NACA 4418 profile was conducted in a water tunnel that also enables control of the cavitation conditions within it. Pressure, lift force, drag force and pitching moment acting on the blade were measured for different blade angles and cavitation numbers, respectively. Relationships between these parameters were elaborated and some of them are presented here in dimensionless form. The analysis of results confirmed that cavitation changes the pressure distribution significantly. As a consequence, lift force and pitching moment are reduced, and the drag force is increased. When the cavitation cloud covers one side of the blade and the flow becomes more and more vaporous, the drag force also begins to decrease. The cavity length is increased by increasing the blade angle and by decreasing thé cavitation number.

This is a preview of subscription content, log in to check access.

Abbreviations

A :

(m2) blade area,B ·L

B :

(m) blade width

C D :

(−) drag coefficient,F D /(p d ·A)

C L :

(−) lift coefficient,F L /(P d ·A)

C M :

(−) pitching moment coefficient,M/(P d ·A ·L)

C p :

(−) pressure coefficient, (p-p r )/p d

F :

(N) force

L :

(m) blade length

M :

(Nm) pitching moment

p :

(Pa) local pressure on blade surface

p d :

(Pa) dynamic pressure,ϱ ·V 2/2

p r :

(Pa) reference wall pressure at blade nose position if there would be no blade in the tunnel

p v :

(Pa) vapor pressure

p 1 :

(Pa) wall pressure 350 mm in front of thé blade axis

Re :

(−) Reynolds number,V ·L/v

V :

(m/s) mean velocity of flow in the tunnel

x :

(m) Cartesian coordinate along thé blade profile cord

x c :

(m) cavity length,x-coordinate of cavity end

α :

(°) blade angle

v (m2/s2):

kinematic viscosity

ρ :

(kg/m3) fluid density

σ :

(−) cavitation number, (p r p v )/p d

ϕ :

(°) angle of tangent to thé blade profile contour

References

  1. Abbott IH;Von Doenhoff AE (1949) Theory of wing sections. McGraw-Hill Book Company, New York

  2. Avellan F; Dupont Ph (1988) Etude de sillage d'une poche de cavitation partielle se développant sur un profil hydraulique bi-dimensionnel. La Houille Blanche No 7/8, pp 507–515

  3. Avellan F; Henry P (1987) Towards the prediction of cavitation erosion: IMHEF Research Program, EPRI Symposium on Power Plant Pump, New Orleans, pp 1–22

  4. Favre J-N; Avellan F; Kuhn de Chizelle Y (1989) Simulation d'écoulement partiellement cavitant sur un profil tronqué monté en veine, confrontation avec des mesures de pression. XXe Journées de l'Hydraulique, Lyon, Paper I-19, pp 1–8

  5. Furuya O; Maekawa S (1982) A theoretical and experimental study on cavitating foils over a full range of cavitation number. IAHR Symposium, Amsterdam, Paper4, pp 1–15

  6. Henry P; Avellan F (1987) The cavitation tunnel at the hydraulic machines and fluid mechanics institute. Vevey, Technical Bulletin, pp 21–24

  7. Matsumoto K; Komiya H; Nagafuji T (1986) Measurement and prediction of the pressure distributions on guide vanes of a Francis turbine. IAHR Symposium, Montreal, Paper 60, pp 1–11

  8. Quang L; Franc J-P; Michel J-M (1989) Analyse expérimentale des pressions statique et dynamique dans la zone de fermeture des poches de cavitation partielle XXe Journées de l'Hydraulique, Lyon, Paper I-15, pp 1–9

  9. Vujanič V; Velenšek B (1991) Influence of cavitation on the forces and on the pitching moment acting on the blade (in Slovene). Kuhljevi dnevi '91, Lipica, pp 228–235

Download references

Author information

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Vujanič, V., Velenšek, B. Influence of cavitation on blade characteristics. Experiments in Fluids 17, 441–445 (1994). https://doi.org/10.1007/BF01877048

Download citation

Keywords

  • Experimental Study
  • Cavitation
  • Pressure Distribution
  • Drag Force
  • Dimensionless Form