fundamentals of fluid film lubrication 2ed

... 2.2 .1) The spatial gradient of velocity, u, can be partitioned into several components with distinctively different roles in fluid dynamics 2 .1 Fluid Dynamics (a) 31 (b) n n S d area V d area ... consequence of the decreases in pressure and density Also, p = p0 1/ κ T θ0 ⇒ p = p0 − gz cp θ0 1/ κ (2. 61) and ρ = p0 Rθ0 p p0 1/ γ (2.62) 46 Fundamental Dynamics Fig 2.6 Vertical...

Ngày tải lên: 09/08/2014, 11:21

... in (2. 118), the associated northward velocity is v = −u0 sin[f t + λ0 ] (2. 121 ) 64 Fundamental Dynamics The solution (2. 120 )- (2. 121 ) is called an inertial oscillation, with a period P = 2 /f ... −g(1 − αθ) , = −g ∂z ρo (2. 104) expressed here as a notational hybrid of (2. 33), (2. 58) and (2. 80) with the simple equation of state, ρ/ρo = − αθ Combining (2. 103)- (2. 104) yields...

Ngày tải lên: 09/08/2014, 11:21

... 100 Barotropic and Vortex Dynamics Again consider the particular situation of a parallel zonal flow (as in Sec 3. 3 .3) with ˆ u = U (y, t) x (3. 96) In the absence of fluctuations or forcing, this ... substantially control the dynamics of 2D turbulent evolution 3. 7 Two-Dimensional Turbulence 1 13 ζ (x,y) t=0 t = 1.25 t = 38 t=4 t = 63 t=8 y x Fig 3. 18 Computational solution...

Ngày tải lên: 09/08/2014, 11:21

... (4. 44) using the relations following (4. 26), the modal form (4. 29), and the dispersion relation (4. 37) A linearized approximation of q from (4. 24) is q− f +ζ f ζ fη f = − ≈ − H H +η H H H (4. 45) ... a∞ = a0 + ξ(a∞ ) (4. 69) From (4. 54) and (4. 59), f X(∞) + v(X(∞)) = =⇒ f x + v =⇒ ξ f X(0) f (x − ξ) v = − f = (4. 70) Inserting (4. 65)- (4. 67) into (4. 70) and evaluating (4. 69) yiel...

Ngày tải lên: 09/08/2014, 11:21

... gn+ .5 ηn+ .5 = φn+1 − φn , n = 1, , N − , (5. 20) and gn+ .5 = g ρn+1 − ρn ρ0 (5. 21) is the reduced gravity for the interface n + The vertical velocity at the interfaces is wn+ .5 = Dηn+ .5 , Dt ... N − (5. 22) And the buoyancy field is bn+ .5 = − 2gn+ .5 ηn+ .5 , Hn + Hn+1 n = 1, , N − (5. 23) Because of the evident similarity among the governing equations, this N -layer model is...

Ngày tải lên: 09/08/2014, 11:21

... ∂K (5 .65 ) or K = 21/4 R (5 .66 ) At this K value, the value for P is P = β R−4 − U R−8 (5 .67 ) 5.2 Baroclinic Instability 183 Therefore, a necessary condition for instability is U > βR2 (5 .68 ) ... influence of β When P < 0, the solution to (5 .62 ) is √ β(2K + R−2 ) i −P C = − ± (5 .69 ) 2K (K + R−2 ) 2K (K + R−2 ) Thus the zonal phase propagation for unstable modes (i.e., the real par...

Ngày tải lên: 09/08/2014, 11:21