##### A converging-diverging nozzle is designed to operate with an exit Mach number of 2. The nozzle...

A converging-diverging nozzle is designed to operate with an exit Mach number of 2. The nozzle is supplied from an air reservoir at 600 kPa and temperature is 300 K. The throat area of the nozzle is 5 cm2.
Determine:

(a) The ratio of exit-to-throat area and exit area.
(b) Given the area ratio in part (a), find the range of back pressure over which the nozzle is choked. What is the critical pressure and design pressure?
Also, calculate the mass flow rate when the nozzle is choked and at design conditons.
(c) Determine the mass flow rate for a back pressure of 450 kPa and 500 kPa.
(d) Determine the mass flow rate for a back pressure of 0 kPa.
(e) Plot pressure variation along centerline of nozzle and mark all the points (back pressures) on it.
(f) Use excel sheet to plot mass variation Vs back pressures and mark all points on it.

In: Mechanical Engineering

##### Interpret typical creep curve and use mathematical analysis to predict creep behaviour

Interpret typical creep curve and use mathematical analysis to predict creep behaviour

In: Mechanical Engineering

##### Why do surfaces absorb solar radiation differently?

1. Why do surfaces absorb solar radiation differently?

In: Mechanical Engineering

##### Graph 2 Substance Ammonia This is an hypothetic Refrigeration cycle. Draw the schematic for this case....

Graph 2
Substance Ammonia
This is an hypothetic Refrigeration cycle.
Draw the schematic for this case. (evaporator, compressors ...)
Sketch the T-s and P-v diagram. 30 points.
Process

State 1 leaving the evaporator at -20 C and 175 kPa

State 2 leaving the Low pressure isentropic compressor at 5.5 bar and enter the high pressure irreversible compressor to state 3

State 3 135 C, 20 bar

State 4 isobaric condenses process (3-4) to saturated liquid

State 5 (4-5) expansion valve to 5.5 bar and enter to a flash chamber
The flash chamber receive the liquid-vapor mixture and separate the vapor and liquid. Its return the vapor to the High pressure compressor entry and the saturated liquid is tag as state 6

State 6 isobaric process to saturated liquid

State 7 (6-7) expansion valve to low pressure line enter the evaporator

In: Mechanical Engineering

##### Problem 3 (36 Pts) The steel pipe is 0.5 m long and has an internal diameter...

Problem 3 (36 Pts)

The steel pipe is 0.5 m long and has an internal diameter of 60 mm and an external diameter of 80 mm. The Young’s modulus E is 200 GPa and the Poisson ratio ν is 0.32. The pipe experiences a twisting moment of 8 kNm and a bending moment of 3.5 kNm.

4p a) Sketch roughly how the angle of rotation and vertical displacement change as a function of distance from the free end of the pipe to the wall.

8p b) Determine the torsion angle and vertical displacement at the free end of the pipe.

6p c) Determine the stress at the top and bottom of the beam at an arbitrary cross- section, say at a-a.

6p d) Determine (i) the principal stress, (ii) the maximum shear stress, and (iii) average normal stress if available.

4p e) Determine whether plastic deformation occurs. Here, the elastic limit for steel is 250 MPa.

4p f) The base of the rod is fastened to the wall by 4 bolts, 2 vertical and 2 horizontal. Analyze different stresses (in normal stress, shear stress, or both) experienced by different bolts.

4p g) If the bolts are 6 mm in diameter and made of the same steel. With the increase of two moments in proportion, which bolt will yield first and how will the yield look like?

In: Mechanical Engineering

##### Heat Q5 A vertical flat plate (1.5 m) height and (1 m) width ,with uniform temperature...

Heat
Q5 A vertical flat plate (1.5 m) height and (1 m) width ,with uniform
temperature (120 oC) one face of this plate expressed to the air with the velocity (6
m/s) to the up direction, the second face expressed to the static air ,the temperature
of the air with two side (30oC) . Calculate the heat losses from the plate. The
properties of the air at (75 oC),[ ρ=0.998 kg/m3
.Cp=1.009 kJ/kg.oC, υ =2.076 *10-5
m
2
/s , k= 0.03 W/m. k]
Nu)L=0.664(ReL)
0.5 (Pr)0.33
for laminar flow
Nu)L=[0.036(ReL)
4/5
-836] (Pr)0.33
for turbulent flow
Nu)L =0.59 (RaL)
0.25
104
< RaL< 109
Nu)L =0.1 (RaL)
0.33
109
< RaL< 1012

In: Mechanical Engineering

##### THERMODYNAMIC The specifications of a typical reciprocating internal combustion engine coupled with a generator are given...

THERMODYNAMIC

The specifications of a typical reciprocating internal combustion engine coupled with a
generator are given in Table Q2. With the aid of a P-v diagram, determine the following
engine performance characteristics by using constant specific heat at room temperature:
i) the total mass contained in the cylinder per cycle,
ii) the mass of fuel burned per cycle,
iii) the mean effective pressure,
iv) the engine power in kW, and
v) the specific fuel consumption in g/kWh .

Table Q2
Item Specification
Cycle 4-stroke
Fuel Type Diesel
Fuel Calorific Value 43 MJ/kg
Combustion Efficiency(%) 95
Compression Ratio 19
No. of Cylinder 4
Engine Capacity (cc) 2000
Intake Pressure (kPa) 95 kPa
Intake Temperature (°C) 30
AFR 28:1
Engine Speed (rpm) 1800

In: Mechanical Engineering

##### A laboratory scale experiment has been planned to study the vortex shedding induced loading on a...

A laboratory scale experiment has been planned to
structural member. For doing this, the accurate
measurements of flow velocity and vortex shedding
frequency is of prime importance. The member is
placed vertically across the flow having mean flow
velocity of 50 m/s. The diameter of the member is 5
cm. If the Strouhal number is 0.2, determine the
following:

appropriate sensor type for measurements and its
characteristics ?

vortex shedding frequency?

sampling frequency required to resolve the
frequency content?

sampling frequency necessary to reconstruct the
waveform and amplitude?

would you filter the signal before acquisition, if yes
then mention reasons?

In: Mechanical Engineering

##### Steam power plants are responsible for the production of most electric power in the world. A...

Steam power plants are responsible for the production of most electric power in the world. A small increase in thermal efficiency can mean large savings from the fuel requirements. Consider a steam power plant that operates on a simple ideal Rankine cycle. Steam is cooled in the condenser at a pressure of 75 kPa by running cooling water at 16°C from the nearby river through the tubes of the condenser. To increase the thermal efficiency of the power cycle, a junior engineer proposed to decrease the operating pressure of the condenser to 2 kPa while maintaining the turbine inlet conditions at constant.

You are asked to assist the junior engineer with the analysis of the feasibility of the proposal. Include the following in your report:

Question:-

Select appropriate turbine inlet conditions (i.e. pressure and temperature) with justifications. Analyse and discuss the effect of the condenser pressure as it is varied from 75 kPa to 2 kPa on the performance of the steam power plant while the turbine is operated and maintained at the selected inlet conditions. Organize relevant data/findings in a table and appropriate charts to illustrate the effect of varying condenser pressure on the performance of the steam power plant. Show one set of detailed sample calculations.

Could you show me a detailed calculation, please.

In: Mechanical Engineering

##### An isotropic sample of a material is subjected to a compressive stress of 230 MPa in...

An isotropic sample of a material is subjected to a compressive stress of 230 MPa in the x direction. However, it is confined so that the sample cannot deform in the y and z directions. Data: Young’s modulus of the block E = 46 GPa Poisson ratio υ = ⅓ Height = 0.5 m Width = 0.5 m Length = 0.5 m Calculate these stresses in the y- and z-directions (in MPa to 2 decimal places) Calculate the strain in the x direction. (% to 2 decimal places) DO NOT INCLUDE UNITS.

X-direction Strain (%)

Y-direction (MPa)

Z-direction (MPa)

In: Mechanical Engineering

##### for my mechatronics class, we are asked to do a project that involves a mechatronic system....

for my mechatronics class, we are asked to do a project that involves a mechatronic system.

I was hoping to also apply some control systems to my project, but cannot think of any good, cost-effective examples to conduct.

tools at my disposal include lab view and an assortment of circuit parts and a bread board with an arduino power supply. I also have a myDAQ port that can connect to LabVIEW.

any ideas are greatly appreciated, as I am struggling to find ideas.

In: Mechanical Engineering

##### 1) How do you calculate the pressure produced by a pump? 2) Draw a simple regulator,...

1) How do you calculate the pressure produced by a pump?

2) Draw a simple regulator, explain its mechanism and its function in a hydraulic system.

3)  How do you specify a hydraulic pump?

In: Mechanical Engineering

##### A commercial refrigerator with refrigerant 134a as the working fluid is used to keep the refrigerated...

A commercial refrigerator with refrigerant 134a as the working fluid is used to keep the refrigerated space at TL = -35°C by rejecting waste heat to cooling water that enters the condenser at 18°C at a rate of 0.25 kg/s and leaves at 26°C. The refrigerant enters the condenser at 1.2 MPa and 50°C and leaves at the same pressure and 41.3°C. If the compressor consumes 3.3 kW of power, determine (a) the mass flow rate of the refrigerant, (b) the refrigeration load, (c) the COP, and (d) the minimum power input to the compressor for the same refrigeration load (e) find out the volume flow rate of refrigerant at the inlet of the condenser in L/min. Assume Th = 18 oC.

In: Mechanical Engineering

##### Al-Amin Stall is already doing their business since 2017 besides the main road to Balik Pulau,...

Al-Amin Stall is already doing their business since 2017 besides the main road to Balik Pulau, Pulau Pinang. This famous stall sells Thai fusion food or also known as “Masakan Panas” among the local people such as Nasi Goreng Kampung, Nasi Goreng Pattaya, Tomyam soup, etc. Besides that, they also served western food such as chicken grill, chicken chop, mushroom soup, lamb grill and fish and chips.

The main problem with this stall is although the stall is famous in Balik Pulau, the business is not in good condition. They always record a small amount of loss at the end of the business month for almost 1.5 years. After visiting the stall, it looks like they didn’t have any specific system to record and track raw material that comes in and out. Besides that, the employee can eat what they want when they work; and not to forget the whole family members make this stall as their second home kitchen where they go and eat anytime they want without paying to the business. They only hire two people to work with them in the kitchen to cook and prepared drinks for the customer.

Besides that, some of the customer complaint that their service too slow. They have to wait quite some time to get their order. On the other hand, their kitchen is crowded with raw material supply where only two people can work there at one time, but the kitchen size is 20 feet x 10 feet. When looking at the dining area, their chairs and table are not ergonomically sound and some of them already broken and no safety at all.

When COVID-19 hit Malaysia, Malaysian government have implemented the Movement Restriction Order (MRO); which gives a massive impact to the stall owner income. The owner thinks it is now the correct time to ask someone who has a background of industrial engineering (which is you) to help him to plan what to do to boost up its business.