Name of the College : Noorul Islam College of Engineering
University : Anna University
Degree : B.E
Department : Aeronautical Engineering
Subject Code/Name : AE 1301 – Flight Dynamics
Document Type : Question Bank
Website : niceindia.com
Download Model/Sample Question Paper :https://www.pdfquestion.in/uploads/niceindia.com/3054-AE_1301-_FLIGHT_DYNAMICS.pdf
Flight Dynamics Question Paper
Part – A
1) What is the need to define ISA and give its values at standard sea level condition? :
Ans : Since atmospheric conditions like pressure, temperature and density are constantly varying with altitude and location of the earth surface, there is a need for a normal atmosphere to use it as standard for the design and flight evaluation of aircraft all over the world. Its standard sea level values are, pressure = 1.013 x105 N/m2, temperature =288K, and density =1.225 kg/m3.
Related : Noorul Islam College of Engineering AE1401 Avionics B.E Question Bank : www.pdfquestion.in/3052.html
2) Distinguish between Troposphere & Stratosphere :
Troposphere :
(a) It extends from earth surface to around 11km altitude.
(b) It is a turbulent region and its temperature decrease linearly at the rate of 6.5C/km 47km (288K to 216K at 11km)
Stratosphere :
(a) It extends from troposphere to about 50 km altitude.
(b) Its temperature remain constant upto about 25km and then increases upto at the rate of 3oC/km. At 47km to 53km, temperature remains constant at 282K.
3) Define Geometric and Geopotential altitudes. Give the relation between ‘g’ at the Absolute altitude (ha) in terms of earth’s surface gravity (go) and geometric altitude (hg) and radius of earth (r) :
Ans :
Geometric altitude (hg) is the physical altitude above the sea level .Geopotential altitude (h) is the fictious altitude and differs from geometric altitude (hg) and is physically compatible with the assumption of constant acceleration due to gravity (go),
5) Define the terms (a) Pressure altitude (b) Temperature altitude (c) Density altitude :
Ans : If an aircraft senses the actual outside air pressure which corresponds to some standard altitude ,then that altitude is called pressure altitude .Similarly if an aircraft senses the actual outside temperature and density which corresponds to some standard altitude , those are called temperature altitude and density altitude respectively.
Part – B
6) What are the factors which decide the flying path of an airplane as a rigid body? :
Ans : Airplane as a rigid body its flying path is decided by ,
a) Its inertia characteristic.
b) Earth‘s acceleration due to gravity
c) Propulsive force generated by power plant
d) Aerodynamic forces (L&D) and moments created on it due to the reaction between airplane and air.
7) Why the airplane is considered as a dynamic system in six degrees of freedom? : What are the conditions to be satisfied for equilibrium along a straight unaccelerated flight path?:
Ans : Airplane motion in air can be completely defined only if six velocity components (linear velocities u,v,w along X,Y,Z axes and angular velocities p,q,r about X,Y,Z ) are given . Hence airplane is considered as a dynamic system in sixdegrees of freedom. For equilibrium along a straight unaccelerated flight path, the equation of static applied to each degree of freedom must be satisfied:
8) What is plane of symmetry of airplane and define symmetric and asymmetric degrees of freedom? :
Ans : Plane of symmetry of airplane is the X-Z plane that divides it into two symmetric halves. Symmetric degrees of freedom are those components of motion related to airplane’s longitudinal motion .They are motions along X and Z axes and about Y-axis . Asymmetric degrees of freedom are those components of motion related to airplane’s lateral motion. They are motions along Y- axis and about X and Z axes .
9) What will decide the lateral (asymmetric) degrees of freedom and define directional stability and dihedral effect :
Ans : Lateral degrees of freedom of an airplane is decided by the direction of relative wind to the plane of symmetry . This angle is called sideslip () and the airplane= is designed to resist the development of sideslip during all normal flight maneuvers .The ability of the airplane to create yawing moments that tend to eliminate any sideslip is called directional stability (sometimes called weathercock stability). The rolling moment created because of sideslip is referred to as dihedral effect . The second type of static lateral stability is associated with the dihedral effect .
10) Define compressibility of fluids and what decides the speed of propagation of small pressure waves in fluids ? :
Ans : Compressibility of fluids (K) is defined as the reciprocal of bulk modulus of fluids ;or it is the volumetric strain (dv/v) developed per unit change in pressure. ( K = -(dv/v)/dp ) .Speed of propagation of small pressure waves (sound waves) is dependent on the elastic property (bulk modulus) of the fluids .
12) What are the different power plants used in airplanes? : Which power plant is most efficient for subsonic airplanes:
Ans : Latest power plants used in airplanes include; propeller driven by reciprocating engines as well as turbines , turbojets ,ramjet and rockets .Here other than rockets all other power plants are using air-breathing engines. Turbojet power plants are most efficient for subsonic airplanes compared to Turboprop, ramjet and rockets. Ramjet and rockets are efficient for short duration supersonic flights whereas turbo propellers are less efficient and can be used only at low speed.