An important application of fluid
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Fluid Mechanics: Fundamentals and Applications
- Define the following dimensionless group number in fluid mechanics, a)Interpretation of force ratio, and what types of application. b)Reynolds number (Re) c)Euler number (Eu) d) Mach number (Ma) e) Weber number (We)arrow_forwardThe heat flux for stable film boiling on the outside of a horizontal cylinder or sphere of diameter D, in m, is given below. What should be the value of "n", for the equation above to be dimensionally consistent? Use dimensional analysis: q=heat flux, W m² W k = thermal conductivity of vapor, 'm °C hgf - [g kỷ Pv(P₁ − Pv)[hfg + 0.4 Cpv (Ts − Tsat)]] à = Cf MyD (Ts - Tsat) Pv = density of vapor, P₁ = density of liquid,- kg m³ kg 'm³ Cpv = enthalpy of vaporization, kg g = gravitatioinal acceleration, C = experimental constant, dimensionless m J kg °C Ts = surface temperature of the heater, °C Tsat = saturation temperature of vapor, °C kg Hv = viscosity of vapor, ms = specific hear of vapor, (Ts - Tsat)arrow_forwardIn making a dimensional analysis, what rules do you followfor choosing your scaling variables?arrow_forward
- Taylor number (Ta) is used here to describe the ratio between the inertia effect and the viscous effect. By applying Buckingham Pi's Theorem, determine an equation for Ta as a function of the radius of inner cylinder (r), cylinder tangential velocity (v), fluid dynamic viscosity (u), gap distance (L) and fluid density (p). Q4arrow_forwardIn fluid mechanics, which of the following are true: (a) Fluid mechanics is the branch of science concerned with stationary fluids (b) Fluids like water posses only potential energy (c) The field of fluid mechanics is infinite and endless (d) It is a branch of physics which concerns the study of liquids and the ways in which they interact with forces (e) It is a sience concerned with the response of fluids to forces exerted upon them, (f) the fluid which is in state of rest is called as static fluid and its study is called as statics.arrow_forwardQ3: The power output (P) of a marine current turbine is assumed to be a function of velocity U, blade length L, angular velocity o, fluid density p and kinematic viscosity v. wL UL (a) Use dimensional analysis to show that, PU3L2 %3D (b) In a full-scale prototype the current velocity U = 2.0 m/s and the angular velocity is w = 15 rpm. A 1:10 scale laboratory model is to be tested in fluid of the same density with angular velocity o = 60 rpm. What velocity should be used in the model tests? (c) If the power output in the model tests is 200 W, what power output would be expected in the prototype?arrow_forward
- Please answer this question using methods of repeating variables/ dimensional analysis. Thank youarrow_forwardQ1: Consider laminar flow over a flat plate. The boundary layer thickness o grows with distance x down the plate and is also a function of free-stream velocity U, fluid viscosity u, and fluid density p. Find the dimensionless parameters for this problem, being sure to rearrange if neessary to agree with the standard dimensionless groups in fluid mechanics. Answer: Q2: The power input P to a centrifugal pump is assumed to be a function of the volume flow Q, impeller diameter D, rotational rate 2, and the density p and viscosity u of the fluid. Rewrite these variables as a dimensionless relationship. Hint: Take 2, p, and D as repeating variables. P e paD? = f( Answer:arrow_forwardMott ." cometer, which we can analyze later in Chap. 7. A small ball of diameter D and density p, falls through a tube of test liquid (p. µ). The fall velocity V is calculated by the time to fall a measured distance. The formula for calculating the viscosity of the fluid is discusses a simple falling-ball vis- (Po – p)gD² 18 V This result is limited by the requirement that the Reynolds number (pVD/u) be less than 1.0. Suppose a steel ball (SG = 7.87) of diameter 2.2 mm falls in SAE 25W oil (SG = 0.88) at 20°C. The measured fall velocity is 8.4 cm/s. (a) What is the viscosity of the oil, in kg/m-s? (b) Is the Reynolds num- ber small enough for a valid estimate?arrow_forward
- Consider steady, incompressible, two-dimensional flow due to a line source at the origin. Fluid is created at the origin and spreads out radially in all directions in the xy-plane. The net volume flow rate of created fluid per unit width is V·/L (into the page of Fig), where L is the width of the line source into the page in Fig Since mass must be conserved everywhere except at the origin (a singular point), the volume flow rate per unit width through a circle of any radius r must also be V·/L. If we (arbitrarily) specify stream function ? to be zero along the positive x-axis (? = 0), what is the value of ? along the positive y-axis (? = 90°)? What is the value of ? along the negative x-axis (? = 180°)?arrow_forwardAn important parameter in fluid flow problemsinvolving thin films is the Weber number (We) which canbe expressed in equation form.where p is the density of the fluid, v is a velocity, L is alength, and O" is the surface tension of the fluid. If the Webernumber is dimensionless, what are the dimensions of thesurface tension O"?arrow_forwardQ4) Set up the differential equations for the two masses [Fig.1] 2cos (3t) Fig. 1 C1 K1 M1 M2 K3arrow_forward
- Principles of Heat Transfer (Activate Learning wi...Mechanical EngineeringISBN:9781305387102Author:Kreith, Frank; Manglik, Raj M.Publisher:Cengage Learning