Concept explainers
Repeat Problem 7.94, but with
Want to see the full answer?
Check out a sample textbook solutionChapter 7 Solutions
Fundamentals of Heat and Mass Transfer
Additional Engineering Textbook Solutions
Thinking Like an Engineer: An Active Learning Approach (4th Edition)
Heating Ventilating and Air Conditioning: Analysis and Design
Engineering Mechanics: Statics & Dynamics (14th Edition)
Thinking Like an Engineer: An Active Learning Approach (3rd Edition)
Automotive Technology: Principles, Diagnosis, and Service (5th Edition)
Statics and Mechanics of Materials (5th Edition)
- Example: In a 45° bend a rectangular air duct of 1 m? cross-sectional area is gradually reduced to 0.5 m² area. Find the magnitude and direction of force required to hold the duct in position if the velocity of flow at 1 m? section is 10 m/s, and pressure is 30 kN/m². Take the specific weight of air as 0.0116 kN/m³. Solution: Fay 45° Fzx PA, cos 45° 45° Vzcos 45° 2. 45°arrow_forwardWater from a large reservoir drives a turbine, and exits as a free jet from a pipe of diameter D. The jet is deflected by a vane, and the horizontal force required to hold the vane is F directed to the left. Given: h = 40m, D = 0.15m, 0 = 30°, F, = 1500N, and Pw = 1000 kg/m³. Assume velocity magnitude at exit of vane is equal to that at entrance. If all losses are negligible, calculate: (a) The power developed by the turbine in kW. (b) The pressure difference across the turbine, and express it as a head (m). h Figure 1: Problem 2, A sketch (not-to-scale) Equations used must be labeled appropriately: conservation of mass, principle of linear momentum, principle of angular momentum, or first law of thermodynamics. Control volumes must be drown and clearly defined. List all assumptions.arrow_forwardQ2 = 10 liter/s DI =? Water D3 = 65mm Tank base area=1 m² rigure 5 (b) A water reservoir (p = 998 kg/m³ ) is being filled through section 1 at Vị = 3 m/s and through section 2 at Q. = 10 litre/s and exit at section 3 at 6.5 m/s which is shown in Figure 5. Calculate the diameter at section 1 so that : i. h is constant, ii. h decrease at 6 mm/s h is constant and section 2 is closed iii. ofarrow_forward
- Problem Set No. 1 1. A 200 kg chunk of lead falls from a height of 30 m and smashes into a rigid concrete floor. Calculate the increase in the internal energy AU (MJ), assuming that no energy is transferred as heat from the lead. 2. Assess the capabilities of a hydroelectric power plant from the following field data: Estimated water flow rate, 40 m³/s River inlet at 1 atm, 10 °C Discharge at 1 atm, 10.2 °C, 200 m below the intake 3. How much energy transfer as heat is required to evaporate completely 1 kg of nitrogen for a constant pressure process, with T = 89.5 K? 4. One kg of CO₂ is heated in a 0.5 m³ vessel from -18 °C to 93 °C. Determine the initial and final states, and the amount of energy transfer as heat to the CO2. 5. The condensate pump on the Navaho power plant raises the water pressure from 3.5 in of mercury to 390 psia at a flow rate of 5,100 gal/min. If the pump isentropic efficiency is 0.8, calculate the power required in hp. 6. Calculate the thermal efficiency of a…arrow_forwardWater flows inside a solid cylindrical pipe, which narrows as it goes up to a height h (see diagram below). The lower horizontal section has circular cross-sectional diameter d, whereas the upper horizontal section has diameter d/2. Let us denote A to be a point at the lower horizontal section and B to be a point at the upper horizontal section. The flow speed at A and B is uд and u, respectively. The pressure at A and B is PA and PB, respectively. РА UA Oom Ja d d/21 1 UB h (a) Assuming water to be incompressible, show that the flow speed at B is four times the flow speed at A. (b) Use Bernoulli's equation to find the drop in the water pressure from A to B. Express the result in terms of h, uд, the density of water p, and the acceleration of gravity g. (c) Above certain critical height h, vapour bubbles start to appear at the top horizontal section, which hinders water flow through the pipe. Explain why this happens.arrow_forwardThe An impeller rotating at 1200 r.p.m. with the following dimensions (b, = 1.5 in., b₂ = 1.0 in., D, 5 in., D₂ = 15 in., ₁= 15°, B₂= 20°, b, and b, are the passage widths at the inlet and outlet with cross-section area A = πDb). impeller develops an actual head of 80 ft and delivers 1000 gpm at the point of maximum efficiency requiring 30 b. hp. Assuming radial inlet flow and neglecting vane thickness. a) draw the virtual velocity diagrams at the inlet and outlet and evaluate all the velocities and angles. virtual head neglecting the circulatory flow c) overall pumn efficiency b)arrow_forward
- A steady flow of room temperaturearrow_forwardPoint 1 P₁ = P 2₁ Sample problem Water flowing at the rate of 0.05 m3/s has a velocity of 40 m/s. The jet strikes a vane and is deflected 120° (Figure). Friction along the vane is negligible and the entire system is exposed to the atmosphere. Potential changes can also be neglected. Determine the force necessary to hold the vane stationary. Water atm Momentum Equation: Σε Point 2 P₂ = Patm 72 = m (Vout-Vin) mungs Control volume Earrow_forwardA reducing bend has a linear velocity at section 1. See Figure 4. The flow is uniform at sections 2 and3. The fluid is incompressible and the flow is steady. The fluid is has specific weight γ = 64.4lb/ft3 and densityρ = 2slug/ft3. Assume unit depth into the page.(a) Find the magnitude and direction of the uniform velocity at section 3.(b) What’s the momentum of the fluid entering the reducer bend?arrow_forward
- - Find V for this mushroom cap on a pipeline. 45° 2 m r 18 m r 3 m3/s – 1 m d Varrow_forwardQ6) A water jet hits horizontally a 50-kg block with a velocity of (20 m/s), see the figure. The friction coefficient between the block and the ground is (0.9). What is the minimum diameter (d) of the water jet required for the block to slide to the left?arrow_forwardAs6. N=35 N2=16 N3=16arrow_forward
- Elements Of ElectromagneticsMechanical EngineeringISBN:9780190698614Author:Sadiku, Matthew N. O.Publisher:Oxford University PressMechanics of Materials (10th Edition)Mechanical EngineeringISBN:9780134319650Author:Russell C. HibbelerPublisher:PEARSONThermodynamics: An Engineering ApproachMechanical EngineeringISBN:9781259822674Author:Yunus A. Cengel Dr., Michael A. BolesPublisher:McGraw-Hill Education
- Control Systems EngineeringMechanical EngineeringISBN:9781118170519Author:Norman S. NisePublisher:WILEYMechanics of Materials (MindTap Course List)Mechanical EngineeringISBN:9781337093347Author:Barry J. Goodno, James M. GerePublisher:Cengage LearningEngineering Mechanics: StaticsMechanical EngineeringISBN:9781118807330Author:James L. Meriam, L. G. Kraige, J. N. BoltonPublisher:WILEY