AERODYNAMICS TR
What is the effect of an expansion fan across the flow of air? A) It increases the speed of the flow B) It decreases the speed of the flow C) It has no effect on the speed of the flow D) It both increases and decreases the speed of the flow depending on the conditions
A) It increases the speed of the flow
What happens to base drag when a jet is present at the center of the base? A) It increases B) It decreases C) It remains unchanged D) It becomes zero
B) It decreases
Provides a simple means of establishing the pressure ratio when the initial Mach number and the relative deflection angle between the freestream and any point on the surface of a body are known. A. Exact Method B. Sufficient Theory C. Approximation Method D. Wing Theory
C. Approximation Method
In exact theory, the air is assumed to be deflected along a plane surface. Whenever the surface in the airstream has curvature, the initial wave will be curved, and the flow will have ____. a. A vorticity b. A separation c. A detachment d. An expansion
a. A vorticity
First-order approximation is also known as: a. Ackeret Theory b. Aerodynamic Theory c. Bernoulli's Principle d. Law of Conservation of Mass
a. Ackeret Theory
A German scientist who has contributed much to the field of supersonic aerodynamics, has suggested a method by which expressions can be simplified to permit easy determination of quantities in Moment and Center of Pressure. a. Adolf Busemann b. George Cayley c. Hans von Ohain d. Jakob Ackeret
a. Adolf Busemann
He is a scientist that has suggested a method by which the expression involving moment of coefficient and center-of-pressure location can be simplified to permit easy determination of these quantities, with one general expression that can be used for all the specifically mentioned symmetrical shapes. a. Adolf Busermann b. Jakob Ackeret c. Robert Goddard d. Charles A. Lindbergh
a. Adolf Busermann
The term ____ is applied to that force which results from the negative (with respect to free stream) pressure on the "base", or flat rear portion of a body. a. Base Drag b. Base Thrust c. Base Lift d. Base Weight
a. Base Drag
I. The solid noses are employed where rocket motors are used for propulsion II. The ducted shapes are not necessary when it is desired to bring air in through the nose as in the case of a ram-jet or turbo-jet. III. The center of pressure of a ducted cone will be ahead of its centroid of planform area owing to the higher lifting pressure toward the lip. IV. When the air enters a ducted body which is at an angle of attack, it can or cannot be deflected through this angle in order to travel through the body. a. Both I and III are true b. Both II and IV are true c. Both II and III are false d. Both I and IV are false
a. Both I and III are true
Which of the statements is true? 1. The optimum contour shape can be determined by a study of the drag and strength characteristics of the various types. 2. The three general contours include the double wedge, the biconvex or double circular arc, and the modified double wedge. a. Both statements are true b. Only statement 1 is true c. Only statement 2 is true d. Both statements are false
a. Both statements are true
The radius of curvature of an ogival surface is usually defined in _____, which is the radius of the arc divided by the diameter of the base. a. Calibers b. Gauges c. Bores d. Sectors
a. Calibers
The radius of curvature of an ogival surface is usually defined in __________, which is the radius of the arc divided by the diameter of the base. a. Calibers b. Ogive c. Ogival Nose d. Tangent Ogive
a. Calibers
It is introduced in the third-order approximation to correct the non-isentropic flow losses across the wave. a. Coefficient "d" b. Coefficient of Pressure c. C3 d. C2
a. Coefficient "d"
Is a function of the sum of the squares of the leading and trailing-edge semi-wedge angles, and it may readily be shown that this is a minimum when the airfoil is completely symmetrical a. Drag Coefficient b. Coefficient of Pressure c. Normal Force d. Base Drag
a. Drag Coefficient
It constitutes a simple method for determining the pressure distribution on airfoils at low angles of attack when not influenced by any third-dimensional effects, i.e. for determining section characteristics of airfoils. a. First-Order Approximation b. Second-Order Approximation c. Third-Order Approximation d. None of the above
a. First-Order Approximation
This theory is the well-known linear, or "Ackeret", or ___________ theory for the two-dimensional pressure change through an oblique shock wave created by deflecting a supersonic stream of air at Mach number M through a small angle θ. a. First-order b. Second-order c. Third-order d. Fourth-order
a. First-order
What is the main characteristic of the "EXACT THEORY" in two-dimensional supersonic flow? a. It involves a change in pressure through an oblique shock wave b. It is based on a set of basic assumptions c. It involves approximation formulas d. It is only a simplification of pressure relationships
a. It involves a change in pressure through an oblique shock wave
First Order Approximation was named after who? a. Jakob Ackeret b. Sir George Cayley c. Vladimir Komarov d. Igor Sikorsky
a. Jakob Ackeret
It can be found from the intersection of the power available and power required curves as they are plotted together. a. Maximum Speed b. Minimum Speed c. Rate of Climb d. Horsepower Available
a. Maximum Speed
_____________ can be used to determine important aerodynamic characteristics of airfoil sections. a. Pressure Coefficient b. Normal Force Coefficient c. Chordwise Force Coefficient d. None of the above
a. Pressure Coefficient
In the application of Pressure Coefficient, a practical approach is to use the ___________ approximation which is more accurate than the ___________ and much simpler than the ___________. a. Second-order; first-order; third-order b. First-order; third-order; second-order c. Third-order; second-order; first-order d. Second-order; third-order; first-order
a. Second-order; first-order; third-order
Moving the point of maximum thickness forward or aft of the mid-chord point changes the lift-curve slope by a _____________ amount. a. Small Second-order b. Small Third-order c. Large Second-order d. Large Third-order
a. Small Second-order
The angle formed by the shock wave and the direction of the upstream flow. a. Wave Angle b. Angle of Attack c. Deflection Angle d. None of the above
a. Wave Angle
The center of pressure of a ducted cone will be _______ of its centroid of plan- form area owing to the higher lifting pressure toward the lip. a. ahead b. below c. above d. on its side
a. ahead
Given the flat plate CN using first order approximation when θ=15° and M=2.2. a. 0.5221 b. 0.5344 c. 0.6879 d. 0.6345
b. 0.5344
It has also been found that a theoretically optimum shape is less than _____ percent better than the biconvex type from the standpoint of drag per unit strength. a. 2 b. 1 c. 3 d. 4
b. 1
In Form Drag equation, K1 constant for Biconvex wing design has a value of: a. 4 b. 5.33 c. 6 d. 2⁄at
b. 5.33
In the function of form drag coefficient formula, biconvex airfoil has a cross-sectional constant value of ___. a. 4 b. 5.33 c. 6 d. 2
b. 5.33
This type of contour on supersonic airfoils is considered to be the optimum practical airfoil cross-sectional shape to give the least drag per unit stress. a. Double wedge type b. Biconvex type c. Modified double wedge type d. Asymmetric type
b. Biconvex type
When the air enters a ducted body which is at an angle of attack, it must be ______ through this angle in order to travel through the body. a. straight b. Deflected c. reflected d. projected
b. Deflected
It refers to the condition of the shock-wave detachment because of the Mach number being too low for the deflection angle rather than because of the boundary layer a. Expansion b. Detachment c. Compression d. None of the above
b. Detachment
This term refers to the condition of the shock-wave due to the Mach number being too low for the deflection angle. a. Linear b. Detachment c. Transverse d. Expansion
b. Detachment
The _________ type of cross section is the optimum shape because it has the least drag for a given thickness ratio; however; in choosing a practical shape for design, the engineer must consider the aspect of strength. a. Flat Plate b. Double-wedge c. Wedge d. Biconvex
b. Double-wedge
When the airfoil is perfectly symmetrical, it can be easily demonstrated that this function, which depends on the squares of the leading and trailing-edge semi-wedge angles, is at a minimum. a. Lift coefficient b. Drag coefficient c. Normal force coefficient d. Total chordwise force coefficient
b. Drag coefficient
The term base drag is applied to that force which results from the negative (with respect to free stream) pressure on the "base", or ______ portion of a body. a. Curve rear b. Flat rear c. Side rear d. Pointed rear
b. Flat rear
The following are the usual assumption when solving under the Exact Theory, except a. The effect of air viscosity and boundary layer formation are neglected b. Flow is assumed rotational c. There is no heat transfer across the shock wave or between the neighboring streamlines d. The leading edge or corner of the surface over which the air is moving must be where the shock wave is associated
b. Flow is assumed rotational
Sufficient Theory is available to permit the estimation of the overall aerodynamic characteristics of cones and ogives, either solid or ducted, when used as the forward portion of a cylinder, as might be expected in the design of the _______ of supersonic aircraft. a. Wing b. Fuselage c. Vertical Tail d. Landing Gear
b. Fuselage
Which one is not an assumption for Exact Theory? a. Flow is irrotational. b. Heat conduction occurs between the adjacent streamlines or across the shock wave. c. Shockwave is attached to the corner or leading edge of the surface over which the air is flowing. d. The flow over the surface is not affected by frictional forces.
b. Heat conduction occurs between the adjacent streamlines or across the shock wave.
EXCEPT for one, the following are the normal assumptions made to allow appropriate relations to be formed when utilizing the exact theory: a. The influence of viscosity is ignored. b. It is believed that the flow is rotating. c. There is no heat transfer between adjacent streamlines or across the shock wave. d. The shock wave must be attached to the leading edge or corner of the surface over which the air flows.
b. It is believed that the flow is rotating.
There are several advantages of the ogival shape. Which of the following statements is one of these advantages? a.It has a slightly greater volume for a given base length and height. b. It is blunter and therefore stronger at the nose (than a corresponding cone shape), in the case of a pointed ogive c. It is blunter and therefore stronger at the nose (than a corresponding cone shape), in the case of a ducted ogive d. It will allow a stronger lip construction, in the case of a pointed ogive.
b. It is blunter and therefore stronger at the nose (than a corresponding cone shape), in the case of a pointed ogive
A Swiss aeronautical engineer known for his research and innovations for supersonic aerodynamics. He led the initial work on calculating the lift and drag on a supersonic airfoil and he proposed the designation of the "Mach number" for multiples of the speed of sound. a. Levi Ackerman b. Jakob Ackeret c. Ludwig Prandtl d. Ernst Mach
b. Jakob Ackeret
Complete the sentence. Based on the assumptions made on exact theory, the shock wave must be attached to the corner or _______ of the surface over which the air is flowing. a. Trailing Edge b. Leading Edge c. Airfoil d. Wing
b. Leading Edge
When using the first-order approximation in determining expansive pressure change, the value of θ employed in the expression must have a ______ sign. a. Positive b. Negative c. Either A or B d. None of the above
b. Negative
The ___________ will be the total difference between the upper and lower pressure differences divided by two. a. Normal Stress coefficient b. Normal Force Coefficient c. Standard Atmosphere Coefficient d. Dynamic Pressure Coefficient
b. Normal Force Coefficient
Considering High Order Approximation, what will be the of the angle in the formula? a. Positive for Normal Shockwave b. Positive for Oblique Shockwave c. Positive for Expansion Wave d. None of the Above
b. Positive for Oblique Shockwave
An ogive in which the center of the arc describing the plan-form of the ogive is on a line normal to the ogive center line at its base so that there is no discontinuity or sharp corner when it is joined to a cylinder of the same diameter as the base. a. Ducted Ogive b. Secant Ogive c. Tangent Ogive d. Pointed Ogive
b. Secant Ogive
Which of the following is NOT an advantage of the ogival shape over the conical shape? a. Blunter and stronger nose b. Slightly higher drag c. Has slightly greater volume for a given base diameter d. Stronger lip construction
b. Slightly higher drag
There are several advantages of the ogival shape which make it an improvement over the conical shape. Which of the following are not advantages of the ogival shape? I. It has a slightly greater volume for a given base diameter and length. II. It has a slightly lower volume for a given base diameter and length. III. An ogive has less form drag than a conical shape of the same length and base diameter. IV. An ogive has more form drag than a conical shape of the same length and base diameter. a. Statement I and III b. Statement II and IV c. Statement I and IV d. Statement II and III
b. Statement II and IV
The SPC in the formula for Coefficient of Pressure for Conical Nose stands for: a. Super Pressure Coefficient b. Surface Pressure Coefficient c. Superlative Pressure Coefficient d. Superidol Pressure Coefficient
b. Surface Pressure Coefficient
The center of the arc descrbing the planform of the ogive is on a line normal to the ogive center line at its base so that there is no discontinuity or sharp corner when it is joined to a cylinder of the same diameter as the base. a. Secant Ogive Nose b. Tangent Ogive Nose c. Cone d. Ogive Nose
b. Tangent Ogive Nose
What is the First-Order Approximation used for in aerodynamics? a. To determine the speed of air b. To determine the pressure distribution on airfoils c. To determine the third-dimensional effects on airfoils d. None of the above
b. To determine the pressure distribution on airfoils
In solving pressure coefficient, θ is ____ since it is an oblique shock wave; θ is ____ since it is an oblique expansion wave. a. negative; positive b. positive; negative c. positive; positive d. negative; negative
b. positive; negative
A ______ is characterized by the center of its arc being on a line normal to the ogive center line, resulting in a seamless connection to a cylinder of equal diameter. a. secant ogive b. tangent ogive c. sine ogive d. cotangent ogive
b. tangent ogive
the general contours that include the most practical types of optimum contour shape for a supersonic wing design includes the following, EXCEPT: a) Double circular arc b) Modified double wedge c) Biconcave spherical arc d) Double wedge
c) Biconcave spherical arc
Find the ratio of maximum thickness to chord length of a biconvex airfoil at 1.5 mach number, and 0.1191824232 sectional drag coefficient. a. 0.03 or 3% b. 0.1 or 10% c. 0.005 or 5% d. 0.5 or 50%
c. 0.005 or 5%
A two-dimensional flat plate is set at an airstream at 47,000 feet pressure altitude and 43,000 feet density altitude at angle of 17 degrees. The ambient airspeed is at 2250 mph. Determine the normal force coefficient, and the upper and lower surface pressure of the plate. a. 0.3643, -0.8457 psi, 5.819 psi b. 0.3678, -6.4288 psi, 33.1727 psi c. 0.3643, -6.4288 kPa, 33.1727 kPa d. 0.3268, -134.3061 psf, 693.0179 psf
c. 0.3643, -6.4288 kPa, 33.1727 kPa
Find the coefficient of pressure of a tangent ogive with a diameter-length ratio of 0.4 at a Mach number of 2. a. 6.4064 b. 0.3145 c. 0.4251 d. 5.4802
c. 0.4251
"___________" means that the radius of the arc forming an ogival surface is 14 times the diameter of the base. a. 14-grade ogive b. 14-class ogive c. 14-caliber ogive d. 14-gauge ogive
c. 14-caliber ogive
Where can be the center of pressure of a ducted cone located? a. Behind the centroid of the planform area b. To the left of the centroid of the planform area c. Ahead of the centroid of the planform area d. To the right of the centroid of the planform area
c. Ahead of the centroid of the planform area
This method provides simple means of determining the change in flow conditions through oblique & expansion waves, particularly pressure distribution to obtain the airfoil section characteristics. a. Approximation Method for Normal Shock and Expansion Wave b. Approximation Method for Oblique Shock and Expensive Wave c. Approximation Method for Oblique Shock and Expansion Wave a. d. Approximation Method for Oblique Shock and Normal Shock Wave
c. Approximation Method for Oblique Shock and Expansion Wave
Its presence will alter the shape somewhat depending on the rate of increase of thickness of the boundary layer and the effect of interaction with the shock wave. a. Detachment b. Flow c. Boundary Layer d. Pressure Distribution
c. Boundary Layer
The ____ of a ducted cone will be ahead of its centroid of planform area due to the higher lifting pressure toward the lip. a. Center of Mass b. Center of Gravity c. Center of Pressure
c. Center of Pressure
Listed below are the three general contours that include the most practical types, except one. a. Double wedge b. Biconvex c. Circular arc d. Modified double wedge
c. Circular arc
The coefficient used for the correction of non-isentropic losses across the wave. It is mainly used for third-order approximation of oblique shock waves. a. Lift Coefficient b. Drag Coefficient c. Coefficient 'd' d. Normal Coefficient
c. Coefficient 'd'
It refers to the condition of the shock-wave detachment because of the Mach number being too low for the deflection angle rather than because of boundary layer. a. Diffraction b. Deflection c. Detachment d. Stall
c. Detachment
The _________ type of cross section is the optimum shape because it has the least drag for a given thickness ratio; however; in choosing a practical shape for design, the engineer must consider the aspect of strength. a. Biconvex b. Flat Plate c. Double-Wedge d. Wedge
c. Double-Wedge
Because of the similarity in the type of flow present on each type, the lift of a ___ ogive will be of the same order of magnitude as that of a ducted cone. a. Tangent Ogive b. Secant Ogive c. Ducted Ogive d. Sine Ogive
c. Ducted Ogive
The "first-order" theory is name after _________ who is a Swiss Aeronautical Engineer and is known for his research and innovations for supersonic aerodynamics a. Hans von Ohain b. George Cayley c. Jakob Ackeret d. Robert H. Goddard
c. Jakob Ackeret
The coefficient "d" corrects this in an oblique shock wave. a. Isentropic flow increase across the wave b. Non-isentropic flow increase across the wave c. Non-isentropic flow losses across the wave d. Isentropic flow losses across the wave
c. Non-isentropic flow losses across the wave
Similar to a cone except that the plan-form shape is formed by segments of arcs rather than by straight lines, a. Tangent Ogive b. Secant Ogive c. Ogive d. 14-caliber Ogive
c. Ogive
Which of the following statement is true? 1. Approximation method provides simple means of determining the change in flow conditions through oblique & normal waves. 2. Approximation method determines pressure distribution to obtain airfoil section characteristics. a. Both 1 and 2 are true b. Only 1 is true c. Only 2 is true d. Both 1 and 2 are false
c. Only 2 is true
The lifting pressure is higher toward the lip of a planform area which will result in the center of pressure of a ducted cone to be ahead of its centroid. The lift of a ducted ogive will be of the _____ order of magnitude as that of the ducted cone because of the similarity of each of their flow. a. Higher b. Lower c. Same d. Zero
c. Same
A ___ is an ogive that is constructed with arcs, however its centers of arcs are aft of the normal to the center line at the base, which then forms a corner when attached to a cylinder. a. Tangent Ogive b. Cosine Ogive c. Secant Ogive d. Cotangent Ogive
c. Secant Ogive
It is also constructed with arcs, but its centers of arc are aft of the normal to the center line at the base, and therefore it forms a corner when attached to a cylinder. a. Ogive b. 14-caliber ogive c. Secant Ogive d. Tangent Ogive
c. Secant Ogive
It is an order approximation which involves the application of pressure coefficient a. First-Order Approximation b. Higher Order Approximation c. Second-Order Approximation d. Third-Order Approximation
c. Second-Order Approximation
From the following statements: I. In determining the pressure change for expansion wave, the value of θ has a positive sign. II. In determining the pressure change for expansion wave, the value of θ has a negative sign. III. In determining the pressure change for oblique shocks, the value of θ has a positive sign. IV. In determining the pressure change for oblique shocks, the value of θ has a negative sign. a. Statements I and II are true. b. Statements I and IV are true. c. Statements II and III are true. d. Statements II and IV are true.
c. Statements II and III are true.
It is available to permit the estimation of the over-all aerodynamic characteristics of cones and ogives, either solid or ducted, when used as the forward portion of a cyclinder, as might be expected in the design of the fuselage of supersonic aircraft a.Exact Theory b. Approximate Theory c. Sufficient Theory d. prandtl Theory
c. Sufficient Theory
One in which the center of the arc describing the plan-form of the ogive is on a line normal to the ogive center line at its base. a. Cosine Ogive b. Secant Ogive c. Tangent Ogive d. Cotangent Ogive
c. Tangent Ogive
These are the three general contours that include the most practical types, except _________. a. The double wedge b. The biconvex or double circular arc c. The modified triple wedge d. The modified double wedge
c. The modified triple wedge
Based on the assumptions of the Exact Theory, no heat conduction between the ____ streamlines or ____ the shock wave. The error incurred by this assumption is negligible. a. undisturbed; aft b. perpendicular; across c. adjacent; across d. parallel; adjacen
c. adjacent; across
The biconvex type may be considered to be the _________ practical airfoil cross-sectional shape to give the ________ drag per unit stress. a. maximum, least b. maximum, greatest c. optimum, least d. optimum greatest
c. optimum, least
In the Exact Theory, the flow is assumed to be irrotational only if: a. the separation and wake effects are likewise neglected b. the flow over the surface is not affected by frictional forces c. when the air is deflected along a plane surface d. when the air is absorbed along a plane surface
c. when the air is deflected along a plane surface
A region of the standard atmosphere that spans the heights of 11-25 km and 47-53 km and has a constant temperature. a) Isentropic Region b) Gradient Region c) Adiabatic Region d) Isothermal Region
d) Isothermal Region
An 8% double wedge airfoil is at M=2.1. What is its sectional drag coefficient? a. 0.0136 b. 0.0137 c. 0.0138 d. 0.0139
d. 0.0139
Solve for the sectional drag coefficient for a 8% biconvex airfoil at M = 1.8. a. 0.0339 b. 0.0340 c. 0.0226 d. 0.0227
d. 0.0227
Which statement is true about Approximation Theory? 1. detachment of the shockwave is not important in these theory 2. the flow needs to be two-dimensional only a. Both are true b. Both are false c. 1 only d. 2 only
d. 2 only
The term that applies to force which results from the negative (with respect to free stream) pressure on the flat rear portion of a body. a. Drag Coefficient b. Coefficient of Pressure c. Normal Force d. Base Drag
d. Base Drag
In supersonic airfoils, the _________ type of airfoil cross section is the optimum shape because it has the least drag for a given thickness ratio. a. Biconvex b. Asymmetric c. Plano-Convex d. Double-Wedge
d. Double-Wedge
The __________ is the sum of the squares of the leading and trailing-edge semi-wedge angles. a. Lift b. Lift Coefficient c. Drag d. Drag Coefficient
d. Drag Coefficient
The principal advantage of an ogival shaped nose over conical shaped ones relative to having same base diameter and length is: a. Higher ground clearance b. Generates turbulent flow c. Shorter take-off distance d. Less form drag
d. Less form drag
In the approximate theory, certain assumptions are made in the derivation of the linear term of the approximation expression. Which of the following is NOT an assumption being considered? a. No Detachment of the shock wave exists either from the leading edge of an airfoil or away from the corner in the case of flow in a corner. b. It is necessary that the flow be perfectly two-dimensional. c. Depending on the rate of increase of the boundary layer thickness and the effect of interaction with the shock wave, the presence of the boundary layer will alter the shape which generally tends to make the boundary layer thicker. d. None of the Above
d. None of the Above
Out of the following, the only supersonic contour generally considered practical is: a. Circular arc with sharp trailing edge b. Supercritical airfoil c. Wedge d. None of the above
d. None of the above
In a two-dimensional symmetric double-wedge airfoil, the first θ can be found by adding the negative value of the angle between the free-stream direction and chord line of wing to the a. Negative Mach angle b. Positive Mach angle c. Negative semi-vertex angle of leading and trailing edges d. Positive semi-vertex angle of leading and trailing edges
d. Positive semi-vertex angle of leading and trailing edges
This is a type of approximation method for Oblique Shock Wave, where a coefficient "d" is introduced to correct for the non-isentropic flow losses across the wave. a. First-Order Approximation b. Higher-Order Approximation c. Second-Order Approximation d. Third-Order Approximation
d. Third-Order Approximation
Which of the statement is false? a. A more practical approach to determine the pressure coefficient is to use the second-order approximation. b. In the third-order approximation, a coefficient "d" is introduced to correct for the non-isentropic flow losses across the wave. c. One of the assumptions that are made when dealing with exact theory is that the shock wave must be attached to the corner or leading edge of the surface over which the air is flowing. d. When solving for the normal force coefficient, the deflection angle should be converted to degrees.
d. When solving for the normal force coefficient, the deflection angle should be converted to degrees.
In dealing with Internal Lift of Ducted Noses, the resultant of the force required to accelerate the air in the new direction creates a resultant force which will depend on: a. dynamic pressure b. mass of air entering the body c. angle of attack d. all of the above
d. all of the above
Which of the following is not an advantage of Ogival shape? a. slightly greater volume for a given base diameter and length b. stronger lip construction, in the case of a ducted ogive c. stronger at the nose, in the case of a pointed ogive d. less form drag than a spherical shape
d. less form drag than a spherical shape
Which of the following is NOT True about Shock expansion theory application a. body made up of straight-line segments b. deflection angles are small enough so no detached shock waves occur c. flow over the body goes through a series OSW and ESW d. pressure distribution (lift and drag) cannot be obtained exactly from OSW & ESW theories
d. pressure distribution (lift and drag) cannot be obtained exactly from OSW & ESW theories
Its centers of arc are aft of the normal to the center line at the base and it forms a corner when attached to a cylinder. a. cone b. ogive c. tangent ogive d. secant ogive
d. secant ogive
The following are the usual assumptions that are made under exact theory except for: Statement I: the effect of viscosity in the air and in the formation of a boundary layer is neglected. Statement II: the flow is assumed to be irrational Statement III: heat conduction exists between the adjacent streamlines or across the shock wave Statement IV: the shock wave must be attached to the corner or leading edge of the surface over which the air is flowing. a.) Statement I, II b.) Statement II only c.) Statement IV only d.) Statement III only
d.) Statement III only