Mention some ways or examples to increase Heat Transfer in an internal flow?
In: Mechanical Engineering
How does gas mileage depend on the type of vehicle (2018 toyota and ford) based on speed, weight, horsepower and temperature? Provide a detailed answer.
In: Mechanical Engineering
Efficiency of an engine operating condition to Carnot cycle is equal to ? = 0.45. Temperature and specific volume of the gaseous working medium at the beginning of isentropic compression are T1 = 600 K and v1 = 0.5 m3/Kg respectively. Find the gas properties at all other characteristic points of the cycle and the amount of heat released during isothermal compression. Assume that the mass of 1Kg of the gas undergoes the sequence of processes corresponding to Carnot cycle. The specific volume of the gas at the end of isothermal expansion is doubled in comparison to specific volume at the end of the adiabatic compression. The particular gas constant and isentropic exponent of the gas is R = 287 KJ/KgK and K= 1.4 respectively. Draw the cycle on p-V and T-s diagram.
In: Mechanical Engineering
0.5 Kg of air at t1 = 327 0C and the specific volume v1 = 0.2 m3/Kg is enclosed in a cylinder under a piston. The gas slowly expands with no friction to the temperature t2 = 0 0C and the specific volume v2 =0.65 m3/Kg (polytrophic process). Find the work and heat of the process and change in internal energy of gas. Determine the initial and final pressure of the gas. The isentropic exponent and particular gas constant for air are equal to k=1.4 and R=287 J/KgK, respectively.
In: Mechanical Engineering
Please answer 3.
3. The airplane from Problem 2 has a maximum speed in steady level flight of 190 kts at 8,000 ft altitude. At this condition, the propeller efficiency is 0.75. Presuming a single reciprocating piston engine, and using the simple models for altitude lapse, compute the maximum shaft brake power in hp that the engine can produce at sea level.
2. Consider an airplane with a wing area of 240 ft2 , a span of 44 ft, an Oswald efficiency of 0.75, and a zero-lift drag coefficient of 240 counts (i.e., CD0=0.024). Presume that the airplane is operating at 8,000 ft altitude at a weight of 7,600 lbs.
In: Mechanical Engineering
A mass of m = 1 Kg of an ideal gas (gas constant R= 278 J/KgK) undergoes two polytropic processes. During the first process temperature increases from 27 0C to 237 0C and volume decreases from 1 m3 to 0.3 m3. During the second process temperature increases to 473 0C and volume is constant. The isentropic exponent of the gas is 1.4. Determine (a) Polytropic exponents (b) missing properties of the gas (c) heat and work of the first process and (d) draw the processes in p-V diagram
In: Mechanical Engineering
14) Generate a Tool design checklist for designing an injection mold.
In: Mechanical Engineering
How is sprue bushing design related to cycle time?
In: Mechanical Engineering
2) What does cooling mold temperatures accomplish?
In: Mechanical Engineering
What are the issues involved in design for serviceability? Obtain an automatic pencil sharpener. Disassemble it. Evaluate its design from serviceability aspect.
In: Mechanical Engineering
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