The Prandtl–Glauert singularity is the prediction by the Prandtl–Glauert transformation that infinite pressures would be experienced by an aircraft as it approaches the speed of sound. Because it is invalid to apply the transformation at these speeds, the predicted singularity does not emerge. This is related to the early 20th century misconception of the impenetrability of the sound barrier.
Reasons of invalidity around Mach 1
The Prandtl–Glauert transformation assumes linearity (i.e. a small change will have a small effect that is proportional to its size). This assumption becomes inaccurate at high Mach numbers and is entirely invalid in places where the flow reaches supersonic speeds, since sonic shock waves are instantaneous (and thus very non-linear) changes in the flow. Indeed, one assumption in the Prandtl–Glauert transformation is approximately constant Mach number throughout the flow, and the increasing slope in the transformation indicates that very small changes will have a very strong effect at higher Mach numbers, thus violating the assumption, which breaks down entirely at the speed of sound.
This means that the singularity featured by the transformation near the sonic speed (M=1) is not within the area of validity. The aerodynamic forces are calculated to approach infinity at the so-called Prandtl–Glauert singularity; in reality, the aerodynamic and thermodynamic perturbations do get amplified strongly near the sonic speed, but they remain finite and a singularity does not occur. The Prandtl–Glauert transformation is a linearized approximation of compressible, inviscid potential flow. As the flow approaches sonic speed, the nonlinear phenomena dominate within the flow, which this transformation completely ignores for the sake of simplicity.
A Prandtl-Glauert singularity on the McDonnell Douglas F/A-18C Hornet Ostrava NATO Days 2022
A Prandtl-Glauert singularity on the McDonnell Douglas F/A-18C Hornet
Full video of training: https://youtu.be/xNqAe15n3WA
REG: HN-427
Finland Air Force
NATO Days / Dny NATO 2022
16.09.2022r.
published: 16 Sep 2022
F-22 Raptor performing a Prandtl-Glauert singularity
An F-22 Raptor doing a flyby creating a Prandtl-Glauert singularity, a result of the compression and rarefaction of the air at the shockfront.
published: 26 Jan 2010
Prandtl–Glauert singularity
Jones Beach Air Show 2009 F/A-18 Super Hornet sonic boom vapor cone.
published: 24 May 2009
The Prandtl-Glauert singularity
published: 09 Oct 2023
Prandtl–Glauert Singularity (Vapor Cloud) on an F/A-18/F
As the U.S. Navy demonstration F/A-18/F approaches show center of the 2015 Dayton Air Show, a Prandtl–Glauert singularity vapor cloud forms and wows the crowds.
published: 20 Jun 2015
Prandtl-Glauert singularity
published: 13 Oct 2012
What Happens as an Object Gets Close to the Sound Barrier? : Physics & Chemistry Education
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The sound barrier is a limit which at regular temperatures and pressures is approximately greater then 300 meters per second. Find out what happens as an object gets close to the sound barrier with help from an experienced physics professional in this free video clip.
Expert: Walter Unglaub
Filmmaker: bjorn wilde
Series Description: Physics is an extraordinarily fascinating topic for a number of important reasons. Get tips on physics and chemistry education with help from an experienced physics professional in this free video series.
published: 05 May 2014
Prandtl-Glauert effect
Prandtl-Glauert effect on a plane close to the sound barrier (a suden descent in pressure causes condensation).
published: 31 Dec 2005
F-18 Prandtl--Glauert Singularity (Subsonic)
F-18 Prandtl--Glauert Singularity. This airplane is not breaking the sound barrier. Chicago Air and Water Show August 2011
published: 26 Aug 2011
1/72 Delta Groove Prandtl-Glauert Singularity NAVY
We are Delta Groove Japan.(www.delta-groove.com/)
New Type 1/72 Diorama!
This is Made of acrylic.
The collection of HobbyMaster Century Wings can be made the best use of.
The inducement light is a fiber cable.
The expression with a delicate this fiber cable is achieved.
It is white LED in both sides for the lighting.
cheap seat dioramas are qualities not compared!
LED light Switch
Accessory:100V-240V AC Adapter
Option:Transparent, acrylic case
Height: 7inch (with case)
Width: 14 inches
Depth: 10.9 inches
Oversea model: $200(with case)+Shipping cost
工場模型や1/500スケールの空港等の製作、販売をしているDeltaGroove ( http://www.delta-groove.com/)です。
Hobby MasterやCENTURY WINGS等1/72の飛行機フィギィアに最適な模型台 です。 板に貼付けるシート製等と違いアクリルを使用しスイッチでLEDが点灯し、コレクションの飛行機を照らします。 「チラシ」と言われる塗装でアスファルトもリアリティある表現を実...
A Prandtl-Glauert singularity on the McDonnell Douglas F/A-18C Hornet
Full video of training: https://youtu.be/xNqAe15n3WA
REG: HN-427
Finland Air Force
NATO Da...
A Prandtl-Glauert singularity on the McDonnell Douglas F/A-18C Hornet
Full video of training: https://youtu.be/xNqAe15n3WA
REG: HN-427
Finland Air Force
NATO Days / Dny NATO 2022
16.09.2022r.
A Prandtl-Glauert singularity on the McDonnell Douglas F/A-18C Hornet
Full video of training: https://youtu.be/xNqAe15n3WA
REG: HN-427
Finland Air Force
NATO Days / Dny NATO 2022
16.09.2022r.
As the U.S. Navy demonstration F/A-18/F approaches show center of the 2015 Dayton Air Show, a Prandtl–Glauert singularity vapor cloud forms and wows the crowds....
As the U.S. Navy demonstration F/A-18/F approaches show center of the 2015 Dayton Air Show, a Prandtl–Glauert singularity vapor cloud forms and wows the crowds.
As the U.S. Navy demonstration F/A-18/F approaches show center of the 2015 Dayton Air Show, a Prandtl–Glauert singularity vapor cloud forms and wows the crowds.
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The sound barrier is a limit...
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http://www.youtube.com/ehoweducation
The sound barrier is a limit which at regular temperatures and pressures is approximately greater then 300 meters per second. Find out what happens as an object gets close to the sound barrier with help from an experienced physics professional in this free video clip.
Expert: Walter Unglaub
Filmmaker: bjorn wilde
Series Description: Physics is an extraordinarily fascinating topic for a number of important reasons. Get tips on physics and chemistry education with help from an experienced physics professional in this free video series.
Subscribe Now:
http://www.youtube.com/subscription_center?add_user=ehoweducation
Watch More:
http://www.youtube.com/ehoweducation
The sound barrier is a limit which at regular temperatures and pressures is approximately greater then 300 meters per second. Find out what happens as an object gets close to the sound barrier with help from an experienced physics professional in this free video clip.
Expert: Walter Unglaub
Filmmaker: bjorn wilde
Series Description: Physics is an extraordinarily fascinating topic for a number of important reasons. Get tips on physics and chemistry education with help from an experienced physics professional in this free video series.
We are Delta Groove Japan.(www.delta-groove.com/)
New Type 1/72 Diorama!
This is Made of acrylic.
The collection of HobbyMaster Century Wings can be made t...
We are Delta Groove Japan.(www.delta-groove.com/)
New Type 1/72 Diorama!
This is Made of acrylic.
The collection of HobbyMaster Century Wings can be made the best use of.
The inducement light is a fiber cable.
The expression with a delicate this fiber cable is achieved.
It is white LED in both sides for the lighting.
cheap seat dioramas are qualities not compared!
LED light Switch
Accessory:100V-240V AC Adapter
Option:Transparent, acrylic case
Height: 7inch (with case)
Width: 14 inches
Depth: 10.9 inches
Oversea model: $200(with case)+Shipping cost
工場模型や1/500スケールの空港等の製作、販売をしているDeltaGroove ( http://www.delta-groove.com/)です。
Hobby MasterやCENTURY WINGS等1/72の飛行機フィギィアに最適な模型台 です。 板に貼付けるシート製等と違いアクリルを使用しスイッチでLEDが点灯し、コレクションの飛行機を照らします。 「チラシ」と言われる塗装でアスファルトもリアリティある表現を実現。 部屋を暗くすれば埋め込まれたLEDの明るい光源も相まって薄暗い照明のようなインテリアとしても最適。
全て手作りによる完成度の高い模型台となっています。
駐機場仕様です。
専用アダプター付属
W: 356mm
D: 276mm
H: 177mm
国内予定価格¥15540(税込み)
We are Delta Groove Japan.(www.delta-groove.com/)
New Type 1/72 Diorama!
This is Made of acrylic.
The collection of HobbyMaster Century Wings can be made the best use of.
The inducement light is a fiber cable.
The expression with a delicate this fiber cable is achieved.
It is white LED in both sides for the lighting.
cheap seat dioramas are qualities not compared!
LED light Switch
Accessory:100V-240V AC Adapter
Option:Transparent, acrylic case
Height: 7inch (with case)
Width: 14 inches
Depth: 10.9 inches
Oversea model: $200(with case)+Shipping cost
工場模型や1/500スケールの空港等の製作、販売をしているDeltaGroove ( http://www.delta-groove.com/)です。
Hobby MasterやCENTURY WINGS等1/72の飛行機フィギィアに最適な模型台 です。 板に貼付けるシート製等と違いアクリルを使用しスイッチでLEDが点灯し、コレクションの飛行機を照らします。 「チラシ」と言われる塗装でアスファルトもリアリティある表現を実現。 部屋を暗くすれば埋め込まれたLEDの明るい光源も相まって薄暗い照明のようなインテリアとしても最適。
全て手作りによる完成度の高い模型台となっています。
駐機場仕様です。
専用アダプター付属
W: 356mm
D: 276mm
H: 177mm
国内予定価格¥15540(税込み)
A Prandtl-Glauert singularity on the McDonnell Douglas F/A-18C Hornet
Full video of training: https://youtu.be/xNqAe15n3WA
REG: HN-427
Finland Air Force
NATO Days / Dny NATO 2022
16.09.2022r.
As the U.S. Navy demonstration F/A-18/F approaches show center of the 2015 Dayton Air Show, a Prandtl–Glauert singularity vapor cloud forms and wows the crowds.
Subscribe Now:
http://www.youtube.com/subscription_center?add_user=ehoweducation
Watch More:
http://www.youtube.com/ehoweducation
The sound barrier is a limit which at regular temperatures and pressures is approximately greater then 300 meters per second. Find out what happens as an object gets close to the sound barrier with help from an experienced physics professional in this free video clip.
Expert: Walter Unglaub
Filmmaker: bjorn wilde
Series Description: Physics is an extraordinarily fascinating topic for a number of important reasons. Get tips on physics and chemistry education with help from an experienced physics professional in this free video series.
We are Delta Groove Japan.(www.delta-groove.com/)
New Type 1/72 Diorama!
This is Made of acrylic.
The collection of HobbyMaster Century Wings can be made the best use of.
The inducement light is a fiber cable.
The expression with a delicate this fiber cable is achieved.
It is white LED in both sides for the lighting.
cheap seat dioramas are qualities not compared!
LED light Switch
Accessory:100V-240V AC Adapter
Option:Transparent, acrylic case
Height: 7inch (with case)
Width: 14 inches
Depth: 10.9 inches
Oversea model: $200(with case)+Shipping cost
工場模型や1/500スケールの空港等の製作、販売をしているDeltaGroove ( http://www.delta-groove.com/)です。
Hobby MasterやCENTURY WINGS等1/72の飛行機フィギィアに最適な模型台 です。 板に貼付けるシート製等と違いアクリルを使用しスイッチでLEDが点灯し、コレクションの飛行機を照らします。 「チラシ」と言われる塗装でアスファルトもリアリティある表現を実現。 部屋を暗くすれば埋め込まれたLEDの明るい光源も相まって薄暗い照明のようなインテリアとしても最適。
全て手作りによる完成度の高い模型台となっています。
駐機場仕様です。
専用アダプター付属
W: 356mm
D: 276mm
H: 177mm
国内予定価格¥15540(税込み)
The Prandtl–Glauert singularity is the prediction by the Prandtl–Glauert transformation that infinite pressures would be experienced by an aircraft as it approaches the speed of sound. Because it is invalid to apply the transformation at these speeds, the predicted singularity does not emerge. This is related to the early 20th century misconception of the impenetrability of the sound barrier.
Reasons of invalidity around Mach 1
The Prandtl–Glauert transformation assumes linearity (i.e. a small change will have a small effect that is proportional to its size). This assumption becomes inaccurate at high Mach numbers and is entirely invalid in places where the flow reaches supersonic speeds, since sonic shock waves are instantaneous (and thus very non-linear) changes in the flow. Indeed, one assumption in the Prandtl–Glauert transformation is approximately constant Mach number throughout the flow, and the increasing slope in the transformation indicates that very small changes will have a very strong effect at higher Mach numbers, thus violating the assumption, which breaks down entirely at the speed of sound.
This means that the singularity featured by the transformation near the sonic speed (M=1) is not within the area of validity. The aerodynamic forces are calculated to approach infinity at the so-called Prandtl–Glauert singularity; in reality, the aerodynamic and thermodynamic perturbations do get amplified strongly near the sonic speed, but they remain finite and a singularity does not occur. The Prandtl–Glauert transformation is a linearized approximation of compressible, inviscid potential flow. As the flow approaches sonic speed, the nonlinear phenomena dominate within the flow, which this transformation completely ignores for the sake of simplicity.