AERODYNAMICS

5- What is the effect of a headwind which is 20% of the landing speed on a landing distance?

6- What is the effect of a tailwind which is 20% of the landing speed on a landing distance?

7- Consider the case of two airplanes of the same type and c.g. position but of different gross weights. The use of the maximum coefficient of braking friction will bring both airplanes to a stop in the same distance. As a result, both airplanes would have identical acceleration and identical stop distances from a given velocity. What is the principal difference between the two airplanes as they reach a stop?

8- In the prediction of takeoff distance from the handbook data. What are the primary considerations must be given for Reciprocating powered airplane and Turbine powered aircraft?

In: Mechanical Engineering

An incompressible fluid oscillates harmonically (V = V0 sin(wt), where V is the velocity) with a certain frequency in a 19 cm diameter pipe. A 1/4 scale model is to be used to determine the pressure difference per unit length, ∆?? at any instant along the pipe. Assume that ∆?? = ?(?, ?0,?,?,?,?)

Where D is the pipe diameter, ω the frequency, t the time, μ the fluid viscosity, and ρ the fluid density.

a) Determine the similarity requirements for the model and the
prediction equation for ∆??.

b) If the same fluid is used in the model and the prototype, and the model frequency is 250 rad/s, what is the prototype frequency?

In: Mechanical Engineering

Provide a brief overview of geoengineering technologies and comment on why they are not more aggressively investigated as climate change solutions?

In: Mechanical Engineering

Discuss the requirements of avionics equipment with respect to following aspects.

(a) Environment

(b) Weight

(c) Reliability.

In: Mechanical Engineering

In an interview, you were asked to prepare a short essay to elaborate the integration process in handling limited resources in engineering project. It requires you to reflect yourself in the Project Manager roles. (Word limit : 700 to 800 )

In: Mechanical Engineering

Explain how air compressor follow both the first and second laws of thermodynamics?

In: Mechanical Engineering

A solar-thermal plant is used to produce power. A molten salt transfers heat to a non-ideal Rankine cycle to produce electricity from a turbine. The molten salt has an average temperature of 800 oC when transferring heat to the boiler in the Rankine cycle. The condenser for the power cycle exchanges heats with water in a river that is at 20 oC. The steam flow rate through the cycle is 10 kg/s. The inlet of the boiler is at 9 MPa absolute and steam leaves the boiler at 9 MPa absolute and 600 oC. The exit of the turbine operates is at 20 kPa absolute and has a quality of 95%. The exit of the condenser is at 20 kPa absolute and is a saturated liquid.

Draw a diagram of the Rankine cycle. Include all the unit operations (pieces of equipment). Show the direction of flow and where heat and work enters and leaves the cycle. Number the streams in the cycle. State proper assumptions.

1. What is the power consumption for the pump (in MW), the power produced by the turbine (in MW), the thermal efficiency of the cycle?

2. What is the maximum thermal efficiency that a heat engine can have operating between the temperatures of the heat source molten salt and heat sink river? Why should the efficiency calculated would be less than this maximum? List at least four places in the cycle that contribute to the real plant having a lower thermal efficiency than the maximum.

In: Mechanical Engineering

A piston-cylinder device initially has a volume of 1.5 m3 containing steam at 300 kPa absolute and 150 oC. It is then heated so it expands at constant pressure until it reaches a temperature of 400 oC.

Draw a diagram of the device showing system boundary and flows of energy. What boundary work is done by the cylinder, in kJ, during the expansion? State your assumptions.

1. What is the mass of steam in the piston-cylinder?

2. How much heat is added to the cylinder, in kJ, during the expansion? State your assumptions.

3. Assuming there are no irreversibilities during the expansion; S.GEN=0, does the entropy of the steam decrease, remain constant, or increase during the expansion? Explain your answer.

In: Mechanical Engineering

- Find a word, number or name.The only restrictions are that it must have at least four characters, and must include at least one horizontal, vertical, angled, and curved segment each [ example: LOVE ].
- Find parameterizations for the each characters in your word, in the xy-plane. At any time the "plotter" can only be at one location and hence the different curves making up your characters must utilize distinct time intervals!
- If F(x,y) = (xy
^{2}) i + (x^{2}y) j is the force field acting on the plotter tip as it traces out your characters, calculate the total work done in plotting your word - Draw typical velocity and acceleration vectors at various points along the curves of each character (on print-out).
- Calculate and graph the speed (as a function of time) along each character.
- Calculate and graph the Normal and Tangential component of the acceleration vectors (as a function of time), at least 2 locations on each character.
- Calculate and graph the curvature (as a function of time) along each character.

In: Mechanical Engineering

Does systematic error vary during repeated readings? What is the relationship between systematic error and the sample size?

In: Mechanical Engineering

- Find a word, number or name.The only restrictions are that it must have at least four characters, and must include at least one horizontal, vertical, angled, and curved segment each [ example: LOVE ].
- Find parameterizations for the each characters in your word, in the xy-plane. At any time the "plotter" can only be at one location and hence the different curves making up your characters must utilize distinct time intervals!

In: Mechanical Engineering

What is the difference between SMC-R50 composite and fabric reinforced composites?

I know SMC uses random fiber orientation, is there a random fiber fabric?

Thanks

In: Mechanical Engineering

If a golf ball were dropped from a significant height and the force of Drag is modeled by Fd=0.0057*V-0.0106, where V is the velocity in m/s the Fd is the force of drag in N. The mass of the golf ball is 0.0455 Kg.

h. How high will the golf ball bounce after the 5th impact with the concrete surface ignore drag force?

i. If drag was included for G and H what type of analysis technique would be needed

In: Mechanical Engineering

Water is discharged from a pipe outlet at a rate of 60l/s at 120.8 kPa absolute pressure. All pipes are 15 cm in diameter with a total length of 200 m. The total pipe length on the suction side is 10.8 m. Both reservoirs are big. The water surfaces are exposed to the atmosphere and the difference in their levels is 9 m.

Pipeline friction head loss is 0.086 m per meter length of pipe. On the suction side, fitting loss is 1.3 m while on the delivery side, fitting loss varies with the square of the velocity with K = 1.0.

a) Find the height of the water level above the pipe outlet in the receiving reservoir (m).

b) Find the total head loss of the system (m).

c) What is the hydraulic power (kW)?

d) The water to be pumped has a vapour pressure of 2335
N/m^{2}. The cavitation parameter, s = 0.12. Find the
maximum pump height possible above the surface of the water in the
supply reservoir (Show clearly the calculation of all heads
involved).]

(Atmospheric pressure = 101.3 kPa).

In: Mechanical Engineering

The stream function ?? in a two-dimensional flow field is given as ?? = 4?? − 3?? + 7???? (a) Prove that this flow field is irrotational and that it satisfies the continuity equation. (b) Find the potential flow function Ф(??, ??) for this flow field with boundary condition Ф = 0 at x = 2, y = 1.

In: Mechanical Engineering