Consider the channel, shown schematically in Figure Q4(a), through which combustion products flow at velocity V and temp
Posted: Fri Apr 29, 2022 10:07 am
Consider the channel, shown schematically in Figure Q4(a),
through which combustion products flow at velocity V and
temperature 800K. The flow direction is from left to right and you
may assume that the flow is one-dimensional and inviscid. The
channel is 1m high. A small disturbance is introduced at the
location indicated in the figure on the lower channel wall and we
observe a Mach wave as sketched in the figure.
i. Calculate the appropriate gas constant for the combustion
products.
ii. Compute the velocity V that will mean that the
distance d behind the disturbance location where the Mach wave hits
the upper wall is equal to 0.9m.
iii. Will the velocity be higher or lower if the Mach wave is in
the same location for an air flow?
(b) A convergent-divergent nozzle is located at the exit of an
engine. A normal shock is present in the divergent part of the
nozzle, i.e. between the throat and nozzle exit. The flow just
upstream of the normal shock wave has a Mach number of 1.9 and the
stagnation pressure in the isentropic part of the flow is
110kPa.
i. Determine the Mach number and static pressure just downstream
of the shock wave.
ii. Calculate the drop in stagnation pressure caused by the
shockwave.
iii. State three (out of five possible) equations that are used
to derive the expression for the static pressure ratio across a
normal shockwave and also state the main assumption used in order
to derive this expression.
[1 m d 1m E Figure 04(a) Mach line small disturbance
through which combustion products flow at velocity V and
temperature 800K. The flow direction is from left to right and you
may assume that the flow is one-dimensional and inviscid. The
channel is 1m high. A small disturbance is introduced at the
location indicated in the figure on the lower channel wall and we
observe a Mach wave as sketched in the figure.
i. Calculate the appropriate gas constant for the combustion
products.
ii. Compute the velocity V that will mean that the
distance d behind the disturbance location where the Mach wave hits
the upper wall is equal to 0.9m.
iii. Will the velocity be higher or lower if the Mach wave is in
the same location for an air flow?
- Consider The Channel Shown Schematically In Figure Q4 A Through Which Combustion Products Flow At Velocity V And Temp 1 (12.84 KiB) Viewed 24 times
engine. A normal shock is present in the divergent part of the
nozzle, i.e. between the throat and nozzle exit. The flow just
upstream of the normal shock wave has a Mach number of 1.9 and the
stagnation pressure in the isentropic part of the flow is
110kPa.
i. Determine the Mach number and static pressure just downstream
of the shock wave.
ii. Calculate the drop in stagnation pressure caused by the
shockwave.
iii. State three (out of five possible) equations that are used
to derive the expression for the static pressure ratio across a
normal shockwave and also state the main assumption used in order
to derive this expression.
[1 m d 1m E Figure 04(a) Mach line small disturbance