Questions
An ideal vapor compression refrigeration cycle using r134a as the refrigerant is being used to cool...

An ideal vapor compression refrigeration cycle using r134a as the refrigerant is being used to cool a house. It provides 3 refrigeration tons ≈ 10.5kW of cooling (heat removal from the house air). The refrigerant in the evaporator operates at 400kPa while in the condenser it is at 1000kPa. Treat the surroundings as a thermal reservoir at 33◦C and the air in the house as a thermal reservoir at 19◦C. All reservoirs are at 100kPa.

1. What is the COPr of this cycle?

2. How fast is exergy destroyed (kJ/s) in each process (evaporator, condenser, throttle, compressor)?

3. Which process has the lowest second law efficiency?

4. What is the rate of exergy destruction (kJ/s) for the cycle?

In: Mechanical Engineering

Consider the flow of a liquid metal past a flat plate (Pr << 1). We have...

Consider the flow of a liquid metal past a flat plate (Pr << 1). We have shown that for a constant wall teemperature, T_o, the Nusselt number is given by Nu = 0.564*(Re^1/2)*(Pr^1/2). Show that if the surface is not a constant temperature, but is instead providing a constant heat flux, that the Nusselt number becomes Nu = 0.886*(Re^1/2)*(Pr^1/2). Start with the following expression for the temperature profile within a semi-infinite body with a constant heat flux boundary condition T - T_o = (q_s / k)[ ((4*alpha*t) / pi)^1/2 * exp(-x^2 / (4*alpha*t)) - x*erfc( x / (4*alpha*t)^1/2 ) ].

In: Mechanical Engineering

Explain how confinement affects detonation properties, specifically in non-ideal high explosives.(Using Annual Review of Fluid Mechanics...

Explain how confinement affects detonation properties, specifically in non-ideal high explosives.(Using Annual Review of Fluid Mechanics
High Explosive Detonation–Confiner Interactions for reference).

In: Mechanical Engineering

In a metallurgy TTT diagram plain carbon steel, pearlite 50% is reached. Is this eutectoid, hypo,...

In a metallurgy TTT diagram plain carbon steel, pearlite 50% is reached. Is this eutectoid, hypo, or hyper and why. Also what is its composition and designation of the alloy.

In: Mechanical Engineering

examine the structure of the materials management processes for these types of items. Specifically, address the...

examine the structure of the materials management processes for these types of items. Specifically, address the following:

What are some necessary considerations when designing a materials management process for bulk and long-lead time items?

How should a project schedule deal with these types of items?

In: Mechanical Engineering

Steam enters an adiabatic turbine at 500C and 4.0MPa and 80m/s. The steam leaves the turbine...

Steam enters an adiabatic turbine at 500C and 4.0MPa and 80m/s. The steam leaves the turbine as saturated liquid-vapor mixture at 30kPa, quality of 92% and 50m/s. The mass flow rate of steam through the turbine is 12kg/s.

(10 pts) Determine change in kinetic energy

(10 pts) Determine the rate of work (power) done by the steam in the turbine, in kW (neglect potential energy change).

(10 pts) Determine the flow area at the entrance to the turbine, in m2. (Hint: use mass flow rate definition).

In: Mechanical Engineering

A tube with a diameter of 6.45 mm was placed in a liquid with a density...

A tube with a diameter of 6.45 mm was placed in a liquid with a density of 998 kg / m3 and it was observed that the liquid increased by 1.44 mm in the tube. Find the surface tension of the fluid [N / m] by taking the contact angle 15 ° between the liquid and the tube surface.

In: Mechanical Engineering

Steam is compressed by an adiabatic compressor from 3 bar and 160°C to 10 bar and...

Steam is compressed by an adiabatic compressor from 3 bar and 160°C to 10 bar and 350°C at a rate of 1.30 kg/s. The power input to the compressor is

626 kW

481.6 kW

370.5 kW

284.8

In: Mechanical Engineering

You drop a 2 kg rock from the edge of a cliff. How much kinetic energy...

You drop a 2 kg rock from the edge of a cliff. How much kinetic energy does the rock have when it has dropped 5 meters down? What speed does it have? [Enter your result for KE in the first answer box and your result for the speed in the second one.]

In: Mechanical Engineering

The following true stresses produce the corresponding true plastic strains for a brass alloy: True Stress...

The following true stresses produce the corresponding true plastic strains for a brass alloy:

True Stress (psi) True Strain
50900 0.10
61300 0.21

What true stress is necessary to produce a true plastic strain of 0.25?

In: Mechanical Engineering

11. Draw a schematic of a swash plate axial piston pump with inclined pistons. Explain briefly...

11. Draw a schematic of a swash plate axial piston pump with inclined pistons. Explain briefly its function and give an expression for its geometric volume.

In: Mechanical Engineering

A 60 kg Drum of diameter 40 cm containing waste material of density 1100 kg/m^3 is...

A 60 kg Drum of diameter 40 cm containing waste material of density 1100 kg/m^3 is being lifted by a steel cable of diameter 30 mm. When the drum is hoisted 10m the natural frequency is measured to be 40 Hz. Determine the volume of the waste in the drum.

In: Mechanical Engineering

G6C5_EOC32 including the following clarifications/additions/modifications: [10] - Interpret “Make two plots on one page.” to mean...

G6C5_EOC32 including the following clarifications/additions/modifications: [10] - Interpret “Make two plots on one page.” to mean in the same Figure Window. - Include grid lines in both plots to make it easier to interpret the plots.

In: Mechanical Engineering

For the case of uniform body forces, show that the plane stress equilibrium equations imply that...

For the case of uniform body forces, show that the plane stress equilibrium equations imply that

2∂ 2 τxy/∂x∂y = − ∂2σx/∂x2 − ∂2σy /∂y2

In: Mechanical Engineering

how is the angle between power strokes determine

how is the angle between power strokes determine

In: Mechanical Engineering