15:39Given-Assign..External Problem 1: Dimensional analysis and similarityA fighter aircraft is to operate at 200 m/s in air at standard conditions (p= 1.2 kg/m³). Amodel is constructed to 1/20 scale (length ratio) and tested in a wind tunnel at the sameair temperature (same air viscosity) to determine the drag force. The drag force Fp is afunction of the air density p and viscosity u, the velocity V and the cross section length ofthe airplane D.a) Use dimensional analysis to prove that:FpVD?and r, =pVDWhat are these two dimensionless numbers?b) If the model is tested at 50 m/s, what air density should be used in the windtunnel? Comment the result and give a recommendation.c) If the model drag force is 250 N at 50 m/s, what will be the drag force of theprototype?Lift force200 m/sDrag forceExternal Problem 2: Dimensional analysis and similarityThe viscous torque T produced on a disc rotating in a liquid depends upon thecharacteristic dimension D, the rotational speed N, the density pand the dynamicviscosity u

Given: Velocity of the prototype (Vp)=200m/sDensity of the fluid in prototype (ρp)=1.2kg/m3Scale…

External Problem 1: Dimensional analysis and similarity A fighter aireraft is to operate at 200 m/s in air at standard conditions (p= 1.2 kg/m³). A model is constructed to 1/20 scale (length ratio) and tested in a wind tunnel at the same air temperature (same air viscosity) to determine the drag force. The drag force Fp is a function of the air density p and viscosity 4, the velocity V and the cross section length of the airplane D. a) Use dimensional analysis to prove that: F and , = pVD What are these two dimensionless numbers? b) If the model is tested at 50 m/s, what air density should be used in the wind tunnel? Comment the result and give a recommendation. c) If the model drag force is 250 N at 50 m/s, what will be the drag force of the prototype? Lift force 200 m/s Drag force

External Problem 1: Dimensional analysis and similarity A fighter aireraft is to operate at 200 m/s in air at standard conditions (p= 1.2 kg/m³). A model is constructed to 1/20 scale (length ratio) and tested in a wind tunnel at the same air temperature (same air viscosity) to determine the drag force. The drag force Fp is a function of the air density p and viscosity 4, the velocity V and the cross section length of the airplane D. a) Use dimensional analysis to prove that: F and , = pVD What are these two dimensionless numbers? b) If the model is tested at 50 m/s, what air density should be used in the wind tunnel? Comment the result and give a recommendation. c) If the model drag force is 250 N at 50 m/s, what will be the drag force of the prototype? Lift force 200 m/s Drag force

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 5.33P

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