Consider an adiabatic, piston cylinder assembly containing 1 kmol of propane (C3H8) and 7 kmol of oxygen (O2). The piston is initially pinned, and the pressure is P1=1000 kPa with temperature T=1000 K. The pin is removed and the system expands until the total cylinder pressure is P2=100 kPa and the temperature is T2=600 K. Assume ideal gases and constant specific heat.
Oxygen: cp=0.918 kJ/kg*K, cv=0.658 kJ/kg*K, MW=32 kmol/kg
Propane: cp=1.67 kJ/kg*K, cv=1.48 kJ/kg*K, MW=44 kmol/kg
Universal gas constant R=8.314 kJ/kmol*K
Find:
a) the mass of propane and oxygen in kg
b) the initial cylinder volume in m3
c) the work produced from state 1 to 2 in kJ
d) the amound of entropy generated from state 1 to 2 in kJ/K
In: Mechanical Engineering
Autonomous driving technology is going on a test run on actual roads in order to become commercialization. As self-driving technology, which has been conducted under controlled experimental conditions, is going to drive on actual roads, it is facing various problems in reality. Self-driving cars, which are being developed at home and abroad, are considered to be much safer than cars driven by humans, but are not yet perfect. Will these cars be able to commercialize only after they have solved all of the various problems they face in the actual driving of the road, or will they be able to be more efficient and safer than human driving vehicles? Explain your opinion about autonomous driving technology with above question and What level of accidents and mistakes can we tolerate in self-driving cars.
In: Mechanical Engineering
A flexible machine part was observed to vibrate excessively at 20 Hz due to a harmonic force of unknown amplitude. It was concluded that vibration was large because the harmonic force coincided with the natural frequency of the flexible part.
When the harmonic force was not present, a 0.5 kg mass was placed on the flexible part and a static displacement of 3.0 mm was observed. The mass was then removed.
a) The flexible part is to be modelled as a one degree-of-freedom, mass-spring-damper system. What mass and stiffness would be appropriate?
b) A tuned vibration absorber is used to eliminate the vibration at 20 Hz. If a mass of 0.03 kg is used for the absorber, what stiffness is required?
c) If the amplitude of the absorber mass at 20 Hz was observed to be1 cm, what is the amplitude of the harmonic force acting on the flexible part?
In: Mechanical Engineering
a high pass rc filter can be changed to a low pass filter by
In: Mechanical Engineering
Why airplanes in War World I was important to society and the problem it solves?
In: Mechanical Engineering
On the surface of a certain component made of aluminium with a modulus of elasticity of 75 GPa and a Poisson’s ratio of 0.35, a strain gauge rosette measures the following strains 0 = –94 × 10-6 60 = 370 × 10-6 120 = 235 × 10-6 The aluminium has a yield strength of 95 MPa. a) Determine the strain components x, y, and xy from the strain gauge measurements. b) Determine values for x, y and xy from the strain components in part (a). c) Determine the magnitude of the principal stresses. d) What is factor of safety according to the maximum distortion energy theory of failure? [20 marks] [40 marks] [40 marks] [20 marks]
In: Mechanical Engineering
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Bill, a process engineer, learns from a former classmate who is now a regional compliance officer with the Occupational Safety and Health Administration (OSHA) that there will be an unannounced inspection of Bill’s plant. Bill believes that unsafe practices are often tolerated in the plant, especially in the handling of toxic chemicals. Although there have been small spills, no serious accidents have occurred in the plant during the past few years. What should Bill do? |
In: Mechanical Engineering
Materials are subject to changes from temperature. We know there are several states of matter; solid, liquid, gas, and plasma. However, within a solid-state, materials have their properties affected, in particular, brittleness. The Liberty ships of the Second World War were often breaking from cold weather.
What causes these failures, what materials are affected, and are there any that are not? How is brittleness calculated and measured (types of measurement) and what does this means for aircraft material selection and design considerations? You may include the influence of this problem from a maintenance perspective. Your work, due in Module 3, is to write a report of a minimum of 2,000 words.
In: Mechanical Engineering
An F/A-18F Super Hornet weighing 22,000 kg is flying at Mach 0.7 at an altitude of 3.5 km. The plane has a length of 18.3 m, a wingspan of 13.6 m and a height of 4.9 m. Assume that the shape of the aircraft can be approximated by a flat rectangular plate.
(a) Calculate the thrust force required to maintain level flight and constant speed.
(b) If the pilot suddenly changes pitch to fly straight up, determine whether he will black-out
(experience more than 9g deceleration) due to the manoeuvre.
(c) Estimate whether the plane would have stopped moving in a horizontal direction before an observer at sea-level heard the manoeuvre. (For a bonus of up to 100 marks, mathematically derive the formula for the final velocity in the horizontal direction and calculate the value at the instant the observer at sea level hears the manoeuvre.)
In: Mechanical Engineering
6.Demonstrate the effect of cold work on the yield strength, tensile strength, percent elongation, Rockwell B hardness, and modulus of elasticity of Red Brass for flat products by plotting these quantities as functions of the percent cold work using EXCEL. Use English system data obtained from www.matweb.comfor HXX tempers.
In: Mechanical Engineering
A SCADA system monitors an application through an RTU out in the field. Please list typical RTU hardware that may be encountered.
In: Mechanical Engineering
What were the pros and cons of forming another strategic alliance (i.e., the Mazda-Toyota partnership) to compete in the automotive industry?
In: Mechanical Engineering
You are to manufacture a smart phone case, material selection question below:
Speicfy the details of the EXACT material grade selected for each of the three material variations of the smart phone case; one metal, one polymer and one carbon-fibre composite (specify the resin type).
- What would be the best choice of material for the phone case from the three options?
In: Mechanical Engineering
Draw a sectional diagram of an aircraft wing, showing the structure of the wing and the control surfaces. Then detail the most appropriate materials used for each of the main parts, mentioning at least 2 metals, 1 CFC composite, and 1 sandwich material and expalin why each is used in that application, with reference to the properties required to withstand the forces involved.
In: Mechanical Engineering
1. Select 3 materials that you think are best for the design of a smart phone back plate cover (not protection case) : One Metal, One Polymer and One Carbon Fibre composite.
2. Specify the details of the EXACT material grade selected for each of the three material variations of the smart phone case(specify the resin type).
3. What would be the best choice of material for the phone case from the three options?
In: Mechanical Engineering