8.8. Consider blood flow in a vessel (i.e., a pipe with a porous wall that is permeable to blood). The radius and length of the vessel are R and L, respectively. In general, the flow is axisymmetric, the fluid velocity has both radial and axial components that are usually determined numerically. However, there are two approximate solutions to this problem. One is to use lubrication theory to determine the relationship between the flow rate and the pressure gradient in the vessel is R<<L. The other is to estimate the axial velocity component by solving a standard problem of unidirectional flow in a pipe with an impermeable wall, but with a different kind of no-slip condition at the wall. The conventional no-slip condition is replaced by the equation: k^1/2 (du/dr)= -a*u

where k is the specific hydraulic permeability of the wall, u is the axial velocity of the fluid, r is the radial coordinate, and a is a dimensionless quantity that depends on the microstructure of the porous wall. The value of a usually varies between 0.1 and 10 depending on the size of the pores in the pipe wall.

(a) Determine the axial velocity profile in the vessel using the second approach.

(b) Find the flow rate through the vessel

(c) Estimate the slip effect a on the pressure drop of the flow rate through the pipe

Water at 300kPa and 20^oC is heated in a chamber by mixing it with superheated steam at 300kPa and 300^oC. The cold water enters the chamber at a rate of 1.9 kg/s. Calculate the mass flow rate of the superheated steam, if the mixture leaves the chamber at 60^oC.

answer is ______kg/s

If necessary, define system and energy flows shown on sketch. Complete solution shown analytically before numbers.

How are the requirements for a design project developed?

Is it possible to design products without any demand? Explain your answer with the likely consequences.

A vapor-compression heat pump with a heating capacity of 500 kJ/min is driven by a power cycle with a thermal efficiency of 30%. For the heat pump, Refrigerant 134a is compressed from saturated vapor at -10°C to the condenser pressure of 10 bar. The isentropic compressor efficiency is 80%. Liquid enters the expansion valve at 9.6 bar, 34°C. For the power cycle, 80% of the heat rejected is transferred to the heated space. (a) Determine the power input to the heat pump compressor, in kW (b) Evaluate the ratio of the total rate that heat is delivered to the heated space to the rate of heat input to the power cycle. Round answers to 3 significant digits.

One kg of Methance (CH4) is burned with 200% theoretical air. What is the air fuel ratio on a mass basis?

Consider a simple Brayton cycle using air as the working fluid with properties assumed constant and evaluated at room temperature (300 K). Conditions at the compressor inlet are T1 = 25°C and P1 = 200 kPa. The pressure ratio is 11 and maximum cycle temperature is 750°C. Answer the following (a) Compute the back?work ratio and cycle efficiency assuming both the turbine and compressor are isentropic (b) Compute the same quantities assuming only the turbine is isentropic while the compressor has an isentropic efficiency of 75% (c) Compute the same quantities assuming only the compressor is isentropic while the turbine has an isentropic efficiency of 75%

Please show all work, assume ideal gas and cold air assumptions and please write legible. Thanks

A 3-phase, 5 kVA, 208 V, four-pole, 60 Hz, Y-connected synchronous machine has negligible stator
winding resistance and a synchronous reactance of 8
per phase at rated terminal voltage. Themachine is operated as a generator and delivers rated kVA at 0.8 power factor lagging.

(a) Determine the excitation voltage,
(b) Find the power angle,
(c) Draw the phasor diagram,
(d) Find the stator current assuming that the field excitation current is now increased by 20 %
(without changing the prime mover power).

what is the enthalpy of formation for c4h8??????????????

A converging nozzle feeds an insulated square duct (L = 224 ft, W = H = 8.0 in, f = 0.02) with air flowing steadily at 7200 lbm/min. The inlet stagnation temperature and stagnation pressure are respectively equal to 116 deg F and 190 psia. Calculate the exit Mach number, exit pressure, exit stagnation pressure and exit stagnation temperature. Ans. 0.67, 70.2 psia, 94.9 psia, 116 deg F.

# Heat Transfer,

Why the ratio of (thermal resistance of conduction)/(thermal resistance of convection) must be less than .1 for a system to lumped.

Why is there this grinding teeth in automatic car system? Is it bad fuel, choice of oil, engine and gear meeting point, bad/faulty gear/transmission system

As speed increases in an engine with throttle body fuel injection, does the temperature of the air-fuel mixture at the intake manifold exit increase or decrease? Explain what parameters affect your answer.