QUESTION 3 a) During a cold winter day, wind at 55 km/h is blowing parallel to a 4-m-high and 10-m-long wall of a house. If the air outside is at 5 °C and the surface temperature of the wall is 12 °C, determine the rate of heat loss from that wall by convection.
Q: Wind loading is a primary consideration in the design of the supporting mechanisms of billboards, as…
A:
Q: the transition point between laminar and turbulent flow A. the boundary layer gets thinner and the…
A: Handwriting.jpg
Q: In the laminar flow of air (Pr = 0.7) over a heated plate, if 8 and 8, denote, respectively, the…
A: Given:Prandtl number, Pr=0.7
Q: For water flowing over a flat plate at 15°C and 3 m/s, calculate the mass flow through the boundary…
A: Given Temperature = 15o C Velocity = 3m/s Distance = 5 cm = 0.05 m To find Mass flow rate
Q: dvantages and disadvantages of fixed wing and rotary wings
A: Advantages and Disadvantages of Fixed wing and Rotary wings Advantages of fixed-wing Increased…
Q: Example 3 The drag coefficient of a car increases when the sunroof is open, and it requires more…
A:
Q: What fluid property is responsible for the development of the velocity boundary layer? What is the…
A: When a fluid flows over any stationary surfaces like flat plate, bed of a river or the wall of a…
Q: Required information -0.5 where x Air flowing over a 1-m-long flat plate at a velocity of 7 m/s has…
A: To obtain the velocity gradient of air on the plate, we must first calculate the shear stress acting…
Q: By which part of the Aircraft is mainly produced the "Induced drag" ??
A: Lift causes induced drag, which is unavoidable.
Q: To reduce the drag coefficient and thus to improve the fuel efficiency, the frontal area of a car is…
A:
Q: Air at 30°C flows over a 3.0-cm-outer-diameter, 45-m-long pipe with a velocity of 6 m/s. Calculate…
A: The projected drag area of the cylinder is The Reynolds number of the flow is The drag coefficient…
Q: Imagine a plate 0.1 m long by 0.1 m wide at a temperature of 80 °C. Water is passed over its…
A: Given data: Ts=80°CT∞=40°CV=0.1 m/sL=0.1 mw=0.1 m Need to determine the heat dissipated by the…
Q: Consider laminar flow of water over a flat plate of length 1 m. If the boundary layer thickness at a…
A:
Q: A boy threw a rubber ball into a lake. The spherical rubber ball has a diameter of 7.5 cm and a…
A:
Q: The known mean velocity is 15.6 mph at a site at a height of 31 ft (about 10m). Approximate the wind…
A: Given data: H1 = 31 ft V1 = 15.6 mph H2 = 100 ft p = 0.3 To find: V2 = ?
Q: To reduce the drag coefficient and thus to improve the fuel efficiency, the frontal area of a car is…
A: Given that, The drag force on the car will be –
Q: In flow over bluff bodies such as a cylinder, how does the pressure drag differ from the friction…
A: The pressure drag is generated due to the shape of the object and it depends on the flow of…
Q: What is the difference in force needed to stabilize a flat plate being sprayed with a jet of water…
A: The force exerted by jet depends on the area of jet or nozzle, velocity of jet coming out through…
Q: Wind flows over a flat plate of length L = 25 mm and width W = 8 mm. The plate is maintained at a…
A:
Q: Water at a velocity of 1.0 m/s flows along the length of one side of a flat plate that is 2 meters…
A:
Q: Thank You!
A: Write the expression of film temperature. Write the property of air 5.75°C from the handbook.
Q: What is the formula and variables in finding the air drag of a motorcycle?
A: Given question: What is the formula and variables in finding the air drag of a motorcycle. The given…
Q: To reduce the drag coefficient and thus to improve the fuel efficiency, the frontal area of a car is…
A: Given details: Ai=18 ft2Ao=15 ft2d=12000 mi=12000×5280=63360000ftv=55…
Q: Q10) A1.8 m-diameter spherical tank of negligible thickness contains iced water at 0°C. Air at 25°C…
A: To find: The rate of heat transfer to the tank. Given: The diameter of tank is 1.8 m. The…
Q: What effect does increasing the Reynolds number have on coefficient of lift and drag?
A: we know that Reynolds no. is defined as the ratio between flow inertia and viscosity.
Q: At highway speeds, about half of the power generated by the car’s engine is used to overcome…
A: Given data: The initial velocity of the car, V1 = 55 mi/h. The final velocity of the car, V2 = 70…
Q: How does the air behaves at zero degree?When is the flow turbulent?When does the boundary layer…
A: The chaotic movement of a gas's particles, according to the physical definition of temperature,…
Q: During a winter day, wind at 70 km/h, 5°C, and 1 atm is blowing parallel to a 4-m-high and 15-m-long…
A: Velocity of wind = 70 km/h = 19.444 m/s The pressure of the air = 1 atm Length of the wall = 15m…
Q: A liquid (? = 850 kg/?3; ? = 1.7 × 10−1 Pa ∙ s) flows tangentially past a flat plate. If the free…
A: 2 Length of the plate, L=10 mWidth of the plate, w=3 mLiquid density, ρ=850 kg/m3Liquid viscosity,…
Q: is the drag coefficient 2 or 0.2?
A: Yes from figure we can see that drag coefficient at 80000 is 0.2 not 2
Q: 1. when , the flow is accelerates if the cross sectional area is increases ( a) M 1 (c) M =1 2. If…
A: Explaining , what is the value of mach number when the cross section area increases in accelerated…
Q: Wind flows over a flat plate of length L = 25 mm and width W = 8 mm. The plate is maintained at a…
A:
Q: In Rizal province, one of its power plants has been thoroughly monitored for possible conversion…
A: Given data : Average Wind speed = 10 miles/hour =4.5 m/s Between 75oF and 90oF , the density of air…
Q: In the laminar flow of air (Pr = 0.7) over a heated plate, if & and 8, denote, respectively, the…
A: Given:Pranddtle number, Pr=0.7δ=hydrodynamic boundary layerδT=Thermal boundary layer
Q: Define the planform area of a body subjected to external flow. When is it appropriate to use the…
A: Planform area: Plan area of an object is taken as the planform area. The plan is the view of the…
Q: Water at 10°C flows over a 4.8-m-long flat plate with a velocity of 1.15 m/s. If the width of the…
A: Given, T = 10°C L = 4.8 m v = 1.15 m/s d = 6.5 m ρ = 999.7 kg/m3 µ = 1.307×10-3 kh/m.s f = ?
Q: Consider a refrigeration truck traveling at 70 mi/h at a location where the air is at 1 atm and…
A: Given that,
Q: Water at 10°C flows over a 1.1-m-long flat plate with a velocity of 0.55 m/s. If the width of the…
A: Given data: The density of water, ρ = 999.7 kg/m3. Dynamic viscosity of water, µ = 1.307×10-3…
Q: How does the construction of a low speed and high-speed aircraft differ? What effects can be…
A: The choice of the airfoil for the airplane wing involves the selection of camber, thickness ratio…
Q: Define the frontal area of a body subjected to external flow. When is it appropriate to use the…
A: Frontal area is the projected area of the body to a plane which is normal to the flow of the fluid.…
Q: What is lift? What causes it? Does wall shear contribute to the lift?
A: given: What is lift? What causes it? Does wall shear contribute to the lift?
Q: A 2-m-high, 4-m-wide rectangular advertisement panel is attached to a 4-m-wide, 0.15-m-high…
A: Given data as per question wind speed = 150 km/h = 150/3.6 m/s width of rectangular advertisement…
Q: An airplane is consuming fuel at a rate of 7 gal/ min when cruising at a constant altitude of 10,000…
A: Take the following assumptions. Standard atmospheric conditions exist. The settings of the plane…
Q: Wind flows over a flat plate of length L = 25 mm and width W = 8 mm. The plate is maintained at a…
A: The flow Reynolds number: Re = 1.6426 × 105 (Laminar flow)
Q: The passenger compartment of a minivan traveling at 50 mi/h in ambient air at 1 atm and 80°F is…
A: Given data *The speed of the minivan is V = 50 mi/h = 50 × 1.46667 ft/s = 73.3335 ft/s *The length…
Q: To reduce the drag coefficient and thus to improve the fuel efficiency, the frontal area of a car is…
A: Given data,
Trending now
This is a popular solution!
Step by step
Solved in 3 steps
- Q2/ An aluminum sphere weighting 7kg and initially at a temperature of 533K is suddenly immersed in a fluid at 283K. if heat transfer coefficient between the sphere and fluid is 50W/m?.°C. Take density=2707kg/m3, specific heat=0.9KJ/kg.°C and thermal conductivity= 204W/m °C. إجابت * Determine the Bi number 0.00696 0.000696 0.0052 0.00052 0 أخری *.Determine the time required to cool sphere to 263K 26.28min 262.8min 52.56 min 525.6 min O أخریAir at atmospheric pressure enters a heating duct with dimensions of 3 x 6 in. The air enters the 16 ft long duct with a temperature of 32 F, and the duct surface is maintained at 150 F. If the air exit temperature is to be 68 F, what is the air flow, in lb/hr? (answer in whole number) For air, R = 53.342 ft-lbf/lbm-R, k = 0.173 Btu-in/ft2-hr-F, and cp = 0.24 Btu/lbm-Subject : Thermofluid Question : A wind turbine four 10 cm diameter cups with a center-to-center distance of 40 cm, as shown in Figure 4. Due to a malfunction, the pivot is suddenly stuck, and the cups stop rotating. If the wind speed is 12 m/s moving at the described direction and air density is 1.25 kg/m3. Determine the maximum torque this turbine applies on the pivot.
- A nuclear reactor is cooled by liquid sodium. The liquid sodium has the following properties: dynamic viscosity = 0.41 mPa·s, specific heat capacity = 1.2 kJ/kgK, thermal conductivity 82 W/mK. Which of the following statements is correct for this scenario? please explain A The thermal boundary layer is thicker than the hydraulic boundary layer. B Heat is transferred through the fluid more easily than momentum. C The velocity varies significantly from the surface to the thickness of the thermal boundary layer. D The hydraulic boundary layer is thicker than the thermal boundary layer.ЕР 7 Fan Selection for Air Cooling of a Computer A fan is to be selected to cool a computer case whose dimensions are 12 cm x 40 cm x 40 cm (see the figure). Half of the volume in the case is expected to be filled with components and the other half to be air space. A 5-cm-diameter hole is available at the back of the case for the installation of the fan that is to replace the air in the void spaces of the case once every second. Small low-power fan-motor combined units are available in the market and their efficiency is estimated to be 30 percent. Determine (a) the wattage of the fan-motor unit to be purchased and (b) the pressure difference across the fan. Take the air density to be 1.20 kg/m. Streamline W elect (2) FanYou are designing an enclosure which houses a PCB. Mounted outside the enclosure on its top is a set of aluminum fins, as seen in the sketch below. The enclosure (and fins) are 150mm deep long. There is no forced airflow. Neglect the thickness of the enclosure walls. Neglect heat transfer out of the sides and bottom of the enclosure. If the PCB produces 4000 W/m2: a) Most industrial-grade ICs have a maximum temperature of 85oC. If you must keep your PCB below this what is the maximum thermal resistance from the PCB to the air surrounding the fins? Assume the air around the fins stays at room temperature. b) If the top of the enclosure (and bottom of the fin base) runs at 50°?, what is the effective thermal conductivity above the PCB? Hint: Because the air inside the enclosure is trapped and heats up, any air properties NOT given below are calculated at the average air temperature (T1+T2)/2. c) What is the temperature at the base of the fins? d) What is the efficiency of the fins? e)…
- Find the minimum amount of diameter for the insulation of a spherical water tank? Radius of the tank is 10 m, thermal conductivity is 25 W/(m^2*K) and convective coefficient is 5 W/(m*K) not sufficient information 8 m 10 m 20 m 15 mSteam at 200 psia and 500°F flows at 100 fps in a 4 inches pipe inside diameter. What is the surface coefficient on the inside of the pipe if the thermal conductivity is 0.255 Btu-in/ft2-hr-°R, Cp = 0.559 Btu/lbs-°R, absolute viscousity is 1.2 x 10-5 lbs/ft-sec and specific volume is 2.725 ft3/lbs. Show your complete solution.O A vertical cylinder 6 ft tall and 1 ft in diameter might be used to approximate a man for heat-transfer purposes. Suppose the surface temperature of the cylinder is 78°F, h=2 Btu/h - ft2 .°F, the surface emissivity is 0.9, and the cylinder is placed in a large room where the air temperature is 68°F and the wall temperature is 45°F. Calculate the heat lost from the cylinder. Repeat for a wall temperature of 80°F. What do you conclude from these calculations?
- Presents the diagram of the problem, necessary formulas, clearance and numerical solution: An iron plate 2 cm thick has a cross-sectional area of 5,000 cm2. One of the faces is at 150 ◦C and the other is at 140 ◦C. How much heat flows through the plate each second? For iron, kT = 80 W/m K.A Deep-sea Diver is wearing a wetsuit in cold water. (Natural convection, radiative transfer is negligible). The following data are given: Water Temperature Te= 10 Degrees Celsius. Wetsuit thickness is equivalent to a 8mm neoprene rubber (thermal conductivity is 0.19 W/m-K), Skin thickness is 1.45mm, Skin thermal conductivity is 0.21 W/m-k. Body temperature below skin Tb= 37 degrees Celsius. Average Air gap thickness is 1mm, air thermal conductivity = 0.027 w/m-K. a) Draw a complete equivalent thermal circuit and show all parameters. b) Calculate the flux of heat loss from the diver (in W/m^2 of body surface area) c) Calculate the temperature of the skin outer surface (Ts) d) Based on your calculations is the wetsuit adequate to keep the diver warm enough? Why?A 50-cm-diameter pipeline in the Arctic carries hot oil at 30°C and is exposed to a surrounding temperature of - 20 degrees * C A special powder insulation 5 cm thick surrounds the pipe and has a thermal conductivity of 7 mW/m °C. The convection heat-transfer coefficient on the outside of the pipe is 9 W / (m ^ 2) °C. Estimate the energy loss from the pipe per meter of length.