KJ_Lesnick
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I have a number of questions here which pertain to supersonic and hypersonic kinetic heating, and the effects of blunt and sharp noses on temperature and drag
FIRST
From what I remember kinetic heating manifests at all speeds, although miniscule and generally insignificant at subsonic speeds, and becomes more pronounced, and undoubtedly significant at supersonic speeds. By the time hypersonic speeds are achieved, this heating effect becomes substantially more extreme.
I remember hearing somewhere that past a certain mach-number range (hypersonic) the rapid rise in kinetic-heating starts to even out (Around Mach 8 to 10 IIRC, but I could be wrong). Is this true, and if so, why does the very rapid rise in temperature start to even out past a given mach number (Mach 8 to Mach 10)?
I am also wondering is this mach-number range Mach 8 to 10 or is it some other figure (higher or lower)?
SECOND
I am aware that blunt-noses (at the expense of drag) produce significant reductions in nose temperatures at hypersonic speeds. However, I am not certain how much of a difference the degree of bluntness (or sharpness for that matter) make on temperature differences. My questions as a result pertain to this issue.
At hypersonic-speeds between Mach-5 and Mach-10
1.) How much of a reduction in kinetic-heating can an aircraft with a highly blunt-nose offer over an aircraft with a mildly blunt-nose?
2.) How much of a reduction in kinetic-heating can an aircraft with a mildly blunt-nose offer over an aircraft with a moderately sharp-nose?
3.) How much of a reduction in kinetic-heating can an aircraft with a moderately sharp-nose offer over an aircraft with a highly sharp-nose?
At hypersonic-speeds between Mach-10 and Mach-15
1.) How much of a reduction in kinetic-heating can an aircraft with a highly blunt-nose offer over an aircraft with a mildly blunt-nose?
2.) How much of a reduction in kinetic-heating can an aircraft with a mildly blunt-nose offer over an aircraft with a moderately sharp-nose?
3.) How much of a reduction in kinetic-heating can an aircraft with a moderately sharp-nose offer over an aircraft with a highly sharp-nose?
At hypersonic speeds between Mach-15 to Mach-25
1.) How much of a reduction in kinetic-heating can an aircraft with a highly blunt-nose offer over an aircraft with a mildly blunt-nose?
2.) How much of a reduction in kinetic-heating can an aircraft with a slightly blunt-nose offer over an aircraft with a moderately sharp-nose?
3.) How much of a reduction in kinetic-heating can an aircraft with a moderately sharp-nose offer over an aircraft with a highly-sharp nose?
To clarify,
When I say a highly blunt-nose I'm talking about the level of bluntness you'd see on a 9mm handgun-round, or the nose of the space-shuttle.
When I say a mildly blunt-object I'm talking about the level of bluntness you'd see on the nose of the X-15
When I say a moderately sharp-nose, I'm talking about the level of sharpness you'd see on an F-8 Crusader, an F-4 Phantom II, or F-14 Tomcat
When I say a highly sharp-nose, I'm talking about the level of sharpness you'd see at the bluntest an F-15 Eagle's nose, to the sharpness seen on the X-3, and X-43's nose (razor sharp)
THIRD
While blunt noses produce reductions in temperature by detatching the shockwave which then results the hottest of the air to be carried away. I am also aware that this unfortunately comes with a serious drag-penalty. I'm not exactly sure how much a difference various nose bluntness or sharpnesses make at those mach numbers. I know there are other factors at work (the airframe), but I'm particularly focused on nose bluntness and sharpness for the purpose of these questions...
At hypersonic-speeds between Mach-5 and Mach-10
1.) How much more drag does a moderately sharp-nose produce over a highly sharp-nose?
2.) How much more drag does a mildly blunt-nose produce over a moderately sharp-nose?
3.) How much more drag does a highly blunt-nose produce over a mildly blunt-nose?
At hypersonic-speeds between Mach-10 and Mach-15
1.) How much more drag does a moderately sharp-nose produce over a highly sharp-nose?
2.) How much more drag does a mildly blunt-nose produce over a moderately sharp-nose?
3.) How much more drag does a highly blunt-nose produce of a mildly blunt-nose?
At hypersonic-speeds between Mach-15 and Mach-25
1.) How much more drag does a moderately sharp-nose produce over a highly sharp-nose?
2.) How much more drag does a mildly blunt-nose produce over a moderately sharp-nose?
3.) How much more drag does a highly blunt-nose produce over a mildly blunt-nose?
To clarify,
When I say a highly blunt-nose I'm talking about the level of bluntness you'd see on a 9mm handgun-round, or the nose of the space-shuttle.
When I say a mildly blunt-object I'm talking about the level of bluntness you'd see on the nose of the X-15
When I say a moderately sharp-nose, I'm talking about the level of sharpness you'd see on an F-8 Crusader, an F-4 Phantom II, or F-14 Tomcat
When I say a highly sharp-nose, I'm talking about the level of sharpness you'd see at the bluntest an F-15 Eagle's nose, to the sharpness seen on the X-3, and X-43's nose (razor-sharp)
I am aware that I have asked questions in the past regarding kinetic heating and mach number, however I did not ask any questions pertaining to the rapid rise in temperatures between Mach-5 to Mach 8-10, followed by a relatively smaller rise from then on.
I also have also, to the best of my knowledge, not asked comprehensive questions regarding the precise degree of heating and drag-levels for various nose bluntnesses/sharpnesses. I have often learned that the more you find out, the more you find out how little you actually know.
KJ Lesnick
BTW: I am not trying to sponge and have done online searches, but I have received so many discrepancies in information I figure it would be best to ask this question on an aviation forum where you have large numbers of members who actually know a few things about aircraft and aerodynamics.
FIRST
From what I remember kinetic heating manifests at all speeds, although miniscule and generally insignificant at subsonic speeds, and becomes more pronounced, and undoubtedly significant at supersonic speeds. By the time hypersonic speeds are achieved, this heating effect becomes substantially more extreme.
I remember hearing somewhere that past a certain mach-number range (hypersonic) the rapid rise in kinetic-heating starts to even out (Around Mach 8 to 10 IIRC, but I could be wrong). Is this true, and if so, why does the very rapid rise in temperature start to even out past a given mach number (Mach 8 to Mach 10)?
I am also wondering is this mach-number range Mach 8 to 10 or is it some other figure (higher or lower)?
SECOND
I am aware that blunt-noses (at the expense of drag) produce significant reductions in nose temperatures at hypersonic speeds. However, I am not certain how much of a difference the degree of bluntness (or sharpness for that matter) make on temperature differences. My questions as a result pertain to this issue.
At hypersonic-speeds between Mach-5 and Mach-10
1.) How much of a reduction in kinetic-heating can an aircraft with a highly blunt-nose offer over an aircraft with a mildly blunt-nose?
2.) How much of a reduction in kinetic-heating can an aircraft with a mildly blunt-nose offer over an aircraft with a moderately sharp-nose?
3.) How much of a reduction in kinetic-heating can an aircraft with a moderately sharp-nose offer over an aircraft with a highly sharp-nose?
At hypersonic-speeds between Mach-10 and Mach-15
1.) How much of a reduction in kinetic-heating can an aircraft with a highly blunt-nose offer over an aircraft with a mildly blunt-nose?
2.) How much of a reduction in kinetic-heating can an aircraft with a mildly blunt-nose offer over an aircraft with a moderately sharp-nose?
3.) How much of a reduction in kinetic-heating can an aircraft with a moderately sharp-nose offer over an aircraft with a highly sharp-nose?
At hypersonic speeds between Mach-15 to Mach-25
1.) How much of a reduction in kinetic-heating can an aircraft with a highly blunt-nose offer over an aircraft with a mildly blunt-nose?
2.) How much of a reduction in kinetic-heating can an aircraft with a slightly blunt-nose offer over an aircraft with a moderately sharp-nose?
3.) How much of a reduction in kinetic-heating can an aircraft with a moderately sharp-nose offer over an aircraft with a highly-sharp nose?
To clarify,
When I say a highly blunt-nose I'm talking about the level of bluntness you'd see on a 9mm handgun-round, or the nose of the space-shuttle.
When I say a mildly blunt-object I'm talking about the level of bluntness you'd see on the nose of the X-15
When I say a moderately sharp-nose, I'm talking about the level of sharpness you'd see on an F-8 Crusader, an F-4 Phantom II, or F-14 Tomcat
When I say a highly sharp-nose, I'm talking about the level of sharpness you'd see at the bluntest an F-15 Eagle's nose, to the sharpness seen on the X-3, and X-43's nose (razor sharp)
THIRD
While blunt noses produce reductions in temperature by detatching the shockwave which then results the hottest of the air to be carried away. I am also aware that this unfortunately comes with a serious drag-penalty. I'm not exactly sure how much a difference various nose bluntness or sharpnesses make at those mach numbers. I know there are other factors at work (the airframe), but I'm particularly focused on nose bluntness and sharpness for the purpose of these questions...
At hypersonic-speeds between Mach-5 and Mach-10
1.) How much more drag does a moderately sharp-nose produce over a highly sharp-nose?
2.) How much more drag does a mildly blunt-nose produce over a moderately sharp-nose?
3.) How much more drag does a highly blunt-nose produce over a mildly blunt-nose?
At hypersonic-speeds between Mach-10 and Mach-15
1.) How much more drag does a moderately sharp-nose produce over a highly sharp-nose?
2.) How much more drag does a mildly blunt-nose produce over a moderately sharp-nose?
3.) How much more drag does a highly blunt-nose produce of a mildly blunt-nose?
At hypersonic-speeds between Mach-15 and Mach-25
1.) How much more drag does a moderately sharp-nose produce over a highly sharp-nose?
2.) How much more drag does a mildly blunt-nose produce over a moderately sharp-nose?
3.) How much more drag does a highly blunt-nose produce over a mildly blunt-nose?
To clarify,
When I say a highly blunt-nose I'm talking about the level of bluntness you'd see on a 9mm handgun-round, or the nose of the space-shuttle.
When I say a mildly blunt-object I'm talking about the level of bluntness you'd see on the nose of the X-15
When I say a moderately sharp-nose, I'm talking about the level of sharpness you'd see on an F-8 Crusader, an F-4 Phantom II, or F-14 Tomcat
When I say a highly sharp-nose, I'm talking about the level of sharpness you'd see at the bluntest an F-15 Eagle's nose, to the sharpness seen on the X-3, and X-43's nose (razor-sharp)
I am aware that I have asked questions in the past regarding kinetic heating and mach number, however I did not ask any questions pertaining to the rapid rise in temperatures between Mach-5 to Mach 8-10, followed by a relatively smaller rise from then on.
I also have also, to the best of my knowledge, not asked comprehensive questions regarding the precise degree of heating and drag-levels for various nose bluntnesses/sharpnesses. I have often learned that the more you find out, the more you find out how little you actually know.
KJ Lesnick
BTW: I am not trying to sponge and have done online searches, but I have received so many discrepancies in information I figure it would be best to ask this question on an aviation forum where you have large numbers of members who actually know a few things about aircraft and aerodynamics.
