Water at 20°C flows over a flat plate with freestream velocity of 0.3 m/s. The plate is 100 cm long (in the flow direction) and 50 cm wide. a. Is the Blasius solution applicable for this flow? Verify with calculation. b. Using Tw(x), evaluate drag force [N] on the plate (one side). c. If the plate is rotated so that the length is 50 cm and width is 100 cm, determine the corre- sponding drag force. Compare with part b. and explain the results. d. Reconsider original plate configuration but with air as the fluid and repeat parts a. and b. Comment on the results.

Water at 20°C flows over a flat plate with freestream velocity of 0.3 m/s. The plate is 100 cm long (in the flow direction) and 50 cm wide. a. Is the Blasius solution applicable for this flow? Verify with calculation. b. Using Tw(x), evaluate drag force [N] on the plate (one side). c. If the plate is rotated so that the length is 50 cm and width is 100 cm, determine the corre- sponding drag force. Compare with part b. and explain the results. d. Reconsider original plate configuration but with air as the fluid and repeat parts a. and b. Comment on the results.

Principles of Heat Transfer (Activate Learning with these NEW titles from Engineering!)

8th Edition

ISBN:9781305387102

Author:Kreith, Frank; Manglik, Raj M.

Publisher:Kreith, Frank; Manglik, Raj M.

Chapter5: Analysis Of Convection Heat Transfer

Section: Chapter Questions

Problem 5.29P: Air at 20C flows at 1 m/s between two parallel flat plates spaced 5 cm apart. Estimate the distance...

See similar textbooks

Similar questions

Q.3 Air (density 1.2 kg/m3 and kinematic viscosity 15 centistokes) flows over a flat plate, at zero angle of incidence, at a velocity of 20 m/s. If Reynolds number at transition is taken as 2.5 × 105, maximum distance, from leading edge up to which the boundary layer remains laminar is
A hydrofoil 51 cm long 4 m wide moves at 1m/s in water at temperature 20 C. Use laminar boundary theory to find,(a) The Drag force and Boundary layer thickness at the trailing edge of the hydrofoil.(b) What would be the effect on Drag force and Boundary layer thickness if water is replaced with CO2 at the same condition?
Some engineers want a good estimate of drag and boundary-layerthickness at the trailing edge of a miniature wing. The chord and span ofthe wing are 6 mm and 30 mm, respectively and a typical flight speed is5 m/s in air (kinematic viscosity = 15 × 10−6 m2/s; density = 1.2kg/m3). An engineer may decide to make a superseding model withchord and span of 150 mm and 750 mm, respectively. Measurements onthe model in a water channel flowing at 0.5 m/s (kinematic viscosity = 1× 10−6 m2/s, density = 1000 kg/m3) give a drag of 0.19 N and aboundary-layer thickness of 3 mm. Estimate the corresponding values forthe prototype
1. The Stokes-Oseen formula for drag force Fon a sphere of diameter D in a fluid stream of low velocity V, density p, and viscosity u is: 9T F = 3TuDV + 16PD? Is this formula dimensionally homogenous? 2. The efficiency n of a pump is defined as the (dimensionless) ratio of the power required to drive a pump: QAp input power Where Q is the volume rate of flow and Ap is the pressure rise produced by the pump. Suppose that a certain pump develops a pressure of Ibf/in? (1ft = 12 in) when its flow rate is 40 L/s (1L =0.001 m). If the input power is 16hp (1hp = 760 W), what is the efficiency?
Using von Karman momentum integral, derive boundary layer height 8, boundary layer displacement thickness d, boundary layer momentum thickness 0, wall shear stress To, local skin friction coefficient c, and total drag coefficient C, for turbulent boundary layer flow with power law constant, n = 5. Discuss by comparing your answers to turbulent boundary layer flow with power law constant, n = 7. Take the empirical wall shear stress: To = 0.0204pU 2 %3D SU 1/4
The momentum thickness OM for laminar flow over a flat plate is (115/1134) 6. Find the following: a) Boundary layer thickness (6) divided by x. Compare this answer to the Blasius Solution. Answer should be 6/x = 5.733/sqrt(Rex). b) Local skin friction coefficient (cf). Answer hould be 0.5814/sqrt(Rex). c) Friction Drag Coefficient. Answer should be 1.1628/sqrt(Rex).
S Algebraic equations such as Bernoulli's relation, Eq. (1) of Ex. 1.3, are dimensionally consistent, but what about differential equations? Consider, for example, the bound- ary-layer x-momentum equation, first derived by Ludwig Prandtl in 1904: ди pu- du pv- ду + pgx + ax ду where 7 is the boundary-layer shear stress and g, is the component of gravity in the x direction. Is this equation dimensionally consistent? Can you draw a general con- cusion?
Baseball drag data from the University of Texas are shownin Fig. A baseball weighs approximately 5.12ounces and has a diameter of 2.91 in. Hall-of-Famer NolanRyan, in a 1974 game, threw the fastest pitch ever recorded:108.1 mi/h. If it is 60 ft from Nolan’s hand to the catcher’smitt, estimate the sea-level ball velocity which the catcherexperiences for (a) a normal baseball, and (b) a perfectlysmooth baseball.
A flat plate of length equal to 50 cm is parallel to a 25 m/s stream velocity. What is the shear stress, in Pa, at a section 40 cm away from the leading edge of the plate? The fluid is air with density equal to 1.2 kg/m³ and kinematic viscosity of 1.5 x 10-5 m²/s. Answer:
The so-called Rocket Man, Yves Rossy, fl ew across the Alps in2008, wearing a rocket-propelled wing-suit with the followingdata: thrust = 200 lbf, altitude = 8,200 ft, and wingspan = 8 ft(http://en.wikipedia.org/wiki/Yves_Rossy). Further assume awing area of 12 ft2, total weight of 280 lbf, CDq = 0.08 for thewing, and a drag area of 1.7 ft2 for Rocket Man. Estimate themaximum velocity possible for this condition, in mi/h.
When a uniform stream flows past an immersed thick cylinder, a broad low-velocity wake is created downstream, idealized as a V shape in Fig. 1. Pressures p1 and p2 are approximately equal. (a) If the flow is two-dimensional and incompressible, with width b into the paper, derive a formula for the drag force F on the cylinder. (b) 1. Rewrite your result in the form of a dimensionless drag coefficient based on body F length Cp pU²bL U = L Fig.1. Airflow on a cylinder U U U/2 L/2 L/2
A buoyant ball of specific gravity SG < 1 dropped intowater at inlet velocity V0 will penetrate a distance h andthen pop out again, as in Fig. Make a dynamicanalysis of this problem, assuming a constant drag coefficient,and derive an expression for h as a function ofthe system properties. How far will a 5-cm-diameterball with SG = 0.5 and CD ≈ 0.47 penetrate if it entersat 10 m/s?