Instead of the control-volume formulation, such as the Reynolds transport theorem (Eqs. 11.5 and 11.6 of WMD), please consult fluid mechanics textbooks such as “Viscous Fluid Flow” by F.M. White (Chapter 1 & 2) and derive the Navior-Stokes equation for a Newtonian fluid flow starting from Newton’s second law: F= ma where F, m, a are the force, mass, and acceleration respectively, following a fluid element. In the derivation you should state (or argue) clearly the assumptions you made and the following key terms:
(1) How the stress and strain rate tensors are defined on a fluid element and their relationship.
(2) the definition of a “Newtonian” fluid,
(3) the definition of the coefficient of viscosity and the coefficient of bulk
viscosity (the second coefficient of viscosity)
(4) the relation between the thermodynamic pressure and the mean flow
pressure
In: Mechanical Engineering
A shell and tube type of heat exchanger with one shell pass and two tube passes will be designed to provide the given heat transfer rate Q(kW) to cool hot water by using cold river water . The hot water flows through the shell and the cold water flows through the tubes. The inlet and outlet temperatures of the hot water and the cold water are given as Thi, The and Tci, Tce in degrees Celcius. Design the shell and tube heat exchanger by making necessary assumptions to calculate the dimensions of the heat exchanger. Q= 10 KW Hot Fluid( Water) Thi= 70 Celcius The= 40 Celcius Cold Fluid ( Water) Tci= 5 Celcius Tce= 15 Celcius 1) Assume the tube diameter and tube length . 2) Assume fouling coefficient based on inside and outside tubes, hdi and hdo . 3) Select the material of construction for the tubes to determine the thermal coefficient. 4) Find the Log Mean Temperature Difference (LMTD) . 5) Obtain the Correction Factor F. 6) Calculate the Mean Temperature Difference. 7) Assume the Overall Heat Transfer Coefficient “U” as initial guess according to type of heat exchanger. 8) Calculate the provisional area. 9) Calculate the number of tubes based on the assumed tube diameter, thickness of the pipe and tube length L. 10) Calculate the tube pitch and bundle diameter. 11) Obtain the bundle diameter clearence. 12) Select the minimum Shell thickness according to nominal shell diameter. 13) Calculate the shell inside diameter 14) Calculate the baffle spacing. 15) Calculate the area for cross flow for the hypothetical row of tubes at the shell equator ( at the shell diameter plane). 16) Calculate the shell side mass flow velocity. 17) Calculate the shell side equivalent diameter ( hydraulic diameter) 18) Calculate the shell side Reynolds number. 19) Calculate or obtain the Prandtl number. 20) Calculate the shell side heat transfer coefficient. 21) Read the friction factor from Jf tablet for the calculated Shell side Reynolds number in order to calculate the shell side pressure drop. 22) Calculate the number of tubes per pass. 23) Calculate the tube-side mass velocity. 24) Calculate the tube-side velocity. 25) Calculate the Prandtl and Reynolds numbers for fluids inside the tubes. 26) Calculate the heat transfer coefficient hi. 27) Calculate the overall heat transfer coefficient “U”. 28) Compare the calculated “U” with that assumed in step 7). If the difference is large , start iteration by changing the tube length till the difference is small enough. 29) Calculate the tube-side pressure drop.
In: Mechanical Engineering
I want an example of the kinetics of rocket with FBD which calculate the curvilinear motion and rectilinear motion
In: Mechanical Engineering
Saturated water vapor at 300F enters a compressor operating at steady state with a mass flow rate of 5 lb/s and is compressed adiabatically to 750 psi.
Determine:
a) The percent isentropic compressor efficiency.
b) The rate of entropy production, in hp/R.
In: Mechanical Engineering
You are the test engineer responsible for the final production testing of an automobile (VW Golf R 2018) - create a list of tests with specifications as well as a block diagram depicting your test plan and the order in which you plan to test the car.
In: Mechanical Engineering
In regards to the Injection Moulding Process. Explain why thicker parts can be more susceptible to shrinkage ,suggest two methods to reduce the shrinkage for a given component geometry?
In: Mechanical Engineering
Why does shrinkage occur in the injection moulding process?
You can use diagrams to assist with your answers if you like.
In: Mechanical Engineering
Explain how the processing parameters for INJECTION MOULDING can influence the tensile strength for a given polymer, explain this in terms of polymer properties.
In: Mechanical Engineering
In regards to the Injection Moulding Process, discuss which polymer properties influence the MFI (melt flow index) and how the individual polymers MFI is related to the various processing parameters for injection moulding. You can use diagrams to assist with your answers if you like.
In: Mechanical Engineering
Identify the key steps in the injection moulding process, explaining how and why temperature, time and pressure are important in each step.
In: Mechanical Engineering
Quesiont is
'Explain Luder's band in detail. Make reference to the yield point, dislocation motion and solute atoms'
In: Mechanical Engineering
You are starting a new job at a plant that makes computer boards. You are responsible for putting the components on the board and also to do soldering. What should you be oriented on? What do you feel is key to your success at this new job? Why?
In: Mechanical Engineering
Define any two (i) PVC (ii) Glass Transition Temperature (iii) LDPE and (iv) Thermoplastics
In: Mechanical Engineering
A double-pipe heat exchanger is designed as an engine oil cooler. The flow rate of oil is 5 kg/s, and it will be cooled from 60°C to 40°C through annulus (ID = 0.10226 m, OD = 0.1143 m). Sea water flows through the tubes (ID = 0.02664 m, OD = 0.03340 m) and is heated from 10°C to 30°C. The number of bare tubes in the annulus is 3, and the length of the hairpin is 3 m. Assume that the tube wall temperature is 35°C. Design calculations give the number of hairpins as 85. Allowable pressure drop in the heat exchanger for both streams is 20 psi. Is this design acceptable? Outline your comments.
In: Mechanical Engineering
For a eutectoid steel, describe isothermal heat treatments that would be required to yield specimens having the following tensile strength-ductility (%RA) combinations:
(a) 900MPa and 30% RA
(b) 700MPa and 25% RA
In: Mechanical Engineering