Consider the wind turbine of Example 1.3. To reduce thenacelle temperature to
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- 3.0 Consider two cases involving parallel flow of dry air at V=V= 1.5 m/s, T∞=T∞=45°C, and atmospheric pressure over an isothermal plate at Ts=Ts=20°C. In the first case, Rex,c=Rex,c=5 × 105, while in the second case the flow is tripped to a turbulent state at x=x=0 m. At what xx‐location, in m, are the thermal boundary layer thicknesses of the two cases equal? What are the local heat fluxes, in W/m2, at this location for the two cases?arrow_forward8. A coal fired steam boiler uses 3000 kg of coal per hour. Air required for combustion is 15.5 kg ofcoal at barometric pressure of 98.2 KPa. The flue gas has temperature of 285 degree Celsiusand an average molecular weight of 30. Assuming an ash loss of 11% and allowable gas velocityof 7.5 meters per second. Find the diameter of the chimney 9. The gas density is 0.75 kg per cubic meters and air density is of 1.15 kg per cubic meter. If thedriving pressure is 0.25 KPA. Determine the height of the chimney. 10. A powerplant situated at an altitude having an ambient air of 96.53 KPa and 23.88 degreeCelsius. Flue gases at a rate of 5.0 kg per second enter the stack at 200 degree Celsius andleaves at 160 degree Celsius. The flue gases gravimetric analysis are 18% CO2, 7% O2 and 75%N2. Calculate the height of the stack necessary for a driving pressure of 0.20 KPaKindly answer all please. Thank youarrow_forwardOne type of supersonic wind tunnel is a blow-down tunnel, where air is stored in a high-pressure reservoir, and then, upon the opening of a valve, exhausted through the tunnel into a vacuum tank or simply into the open atmosphere at the downstream end of the tunnel. For this example, weconsider just the high-pressure reservoir as a storage tank that is being charged with air by a high-pressure pump. As air is being pumped into the constant-volume reservoir, the air pressure inside the reservoir increases. The pump continues to charge the reservoir until the desired pressure is achieved.Consider a reservoir with an internal volume of 30 m3. As air is pumped into the reservoir, the air pressure inside the reservoir continually increases with time. Consider the instant during the charging process when the reservoir pressure is 10 atm. Assume the air temperature inside the reservoir is held constant at 300 K by means of a heat exchanger.Air is pumped into the reservoir at the rate of 1…arrow_forward
- Consider two cases involving the parallel flow of dry air at V= 1.5 m/s, T∞=45°C, and atmospheric pressure over an isothermal plate at Ts=20°C. In the first case, Rex,c=R5 × 105, while in the second case the flow is tripped to a turbulent state at x=0 m. At what x‐location, in m, are the thermal boundary layer thicknesses of the two cases equal? What are the local heat fluxes, in W/m2, at this location for the two cases?arrow_forward4.2. The ball catathermometer factor (F) is 620, time while the spirit column drops from 38 to 350C in 100 seconds and the air temperature is 260C. Determine the air movement speed for the industrial section with these parameters.arrow_forwardWhat is the critical value of the pressure coefficient for an airplane flying at 170m/s in air at 2 deg C?arrow_forward
- An expression for the laminar velocity profile on a flat plate is u=C1sin(C2y)+C3 Where the argument of the sine function is in radians. Using the three common physicalconditions that the velocity profile should satisfy, determine d) the skin friction coefficient, Cf as a function of lengthe) displacement thickness (δ*/x) as a function of lengthf) the momentum thickness (θ/x) as a function of lengthg) the drag force (FD) on both sides of the platearrow_forwardAir flows inside a tube 60 mm in diameter (d) and 2.1 m long (l) at a velocity w = 5 m/sec. Find the heat-transfer coefficient α if the mean air temperature tf = 100oC. Note: Write your answer in space provided without the unit (the answer is in kcal/m2-hr-oC, one decimal places)arrow_forwardAn air cannon uses compressed air to propel a projectile from rest to a final velocity. Consider an air cannon that is to accelerate a 10-gram projectile to a speed of 300 m/s using compressed air, whose temperature cannot exceed 20°C. The volume of the storage tank is not to exceed 0.1 m3 . Select the storage volume size and maximum storage pressure that require the minimum amount of energy to fill the tank.arrow_forward
- A gasoline engine is at a location where the temperature is measured to be 14.2 °C and produces 347 KW at 5800 rpm while consuming 0.0184 kg's of fuel. During operation, data shows that its mechanical energy loss is 18 %, the actual volume of air going into each cylinder is 80% (the volumetric efficiency has a negligible variation), and the actual fuel-to-air ratio is 0.065. What were the engine parameters at sea level conditions if the pressure here is 100.3 kPa and the temeratur here is 18 Uc hotter than that of the alevated conditions? Determine at sea-level conditions the ISFC in ka/kW-hr Use four (4) decimal places in your solution and answer.arrow_forwardConsider a Lear jet flying at a velocity of 250 m/s at an altitude of 10 km,where the density and temperature are 0.414 kg/m3 and 223 K,respectively. Consider also a one-fifth scale model of the Lear jet beingtested in a wind tunnel in the laboratory. The pressure in the test section ofthe wind tunnel is 1 atm = 1.01 × 105 N/m2. Calculate the necessaryvelocity, temperature, and density of the airflow in the wind-tunnel testsection such that the lift and drag coefficients are the same for thewind-tunnel model and the actual airplane in flight.arrow_forwardExample 2: The local atmospheric pressure in Denver, Colorado (elevation 1610 m), is 83.4 kPa. Air at this pressure is 20°C flows with a velocity of 8 m/s over a 1.5 m 6 m flat plate whose temperature is 140°C (Figure). Determine the rate of heat transfer from the plate if the air flows parallel to the (a) 6-m-long side and (b) the 1.5-m side.arrow_forward
- Principles of Heat Transfer (Activate Learning wi...Mechanical EngineeringISBN:9781305387102Author:Kreith, Frank; Manglik, Raj M.Publisher:Cengage Learning