FRINK Linked Data Fragments server

Matches in SemOpenAlex for { <https://semopenalex.org/work/W135888470> ?p ?o ?g. }

• W135888470 abstract "Calculation of sonic boom signatures for aircraft has traditionally followed the methods of Whitham' and Walkden. The wave disturbance generated by the vehicle is obtained by area rule linearized supersonic flow methods, which yield a locally axisymmetric asymptotic solution. This solution is acoustic in nature, i.e., first order in disturbance quantities, and corresponds to ray acoustics. Cumulative nonlinear distortion of the signature is incorporated by using this solution to adjust propagation speed to first order, thus yielding a solution second order in disturbance quantities. The effects of atmospheric gradients are treated by Blokhintzov's method of geometrical acoustics. Both nonlinear signature evolution and ray tracing are applied as if the pressure field very close to the vehicle were actually that given by the source term (the 'F-function') of the asymptotic linearized flow solution. The viewpoint is thus that the flow solution exists at a small radius near the vehicle, and may be treated as an input to an extrapolation procedure consisting of ray tracing and nonlinear aging. The F-function is often regarded as a representation of a near-field pressure signature, and it is common for computational implementations to treat it interchangeably with the pressure signature. There is a 'matching radius' between the source function and the subsequent propagation extrapolation. This viewpoint has been supported by wind tunnel tests of simple models, and very typically yields correct results for actual flight vehicles. The assumption that the F-function and near-field signature are interchangeable is generally not correct. The flowfield of a vehicle which is not axisymmetric contains crossflow components which are very significant at small radii and less so at larger distances. From an acoustical viewpoint, the crossflow is equivalent to source diffraction portions of the wave field. Use of the F-function as a near field signature effectively assumes that the diminution of the crossflow/diffraction component may be applied all at once at the matching radius noted above. This approximation, though not rigorously validated, is responsible for the usual correct far-field results. On the other hand, if an actual near-field signature (either from wind tunnel or CFD data) is used at a starting point rather than one based on th effective source distribution, the predicted far-field signature is generally wrong." @default.
• W135888470 created "2016-06-24" @default.
• W135888470 creator A5007089326 @default.
• W135888470 date "1996-07-01" @default.
• W135888470 modified "2023-09-23" @default.
• W135888470 title "Theoretical Basis for Finite Difference Extrapolation of Sonic Boom Signatures" @default.
• W135888470 hasPublicationYear "1996" @default.
• W135888470 type Work @default.
• W135888470 sameAs 135888470 @default.
• W135888470 citedByCount "0" @default.
• W135888470 crossrefType "journal-article" @default.
• W135888470 hasAuthorship W135888470A5007089326 @default.
• W135888470 hasConcept C121332964 @default.
• W135888470 hasConcept C132459708 @default.
• W135888470 hasConcept C134306372 @default.
• W135888470 hasConcept C158622935 @default.
• W135888470 hasConcept C205991772 @default.
• W135888470 hasConcept C2524010 @default.
• W135888470 hasConcept C33923547 @default.
• W135888470 hasConcept C38349280 @default.
• W135888470 hasConcept C47338736 @default.
• W135888470 hasConcept C57879066 @default.
• W135888470 hasConcept C62520636 @default.
• W135888470 hasConceptScore W135888470C121332964 @default.
• W135888470 hasConceptScore W135888470C132459708 @default.
• W135888470 hasConceptScore W135888470C134306372 @default.
• W135888470 hasConceptScore W135888470C158622935 @default.
• W135888470 hasConceptScore W135888470C205991772 @default.
• W135888470 hasConceptScore W135888470C2524010 @default.
• W135888470 hasConceptScore W135888470C33923547 @default.
• W135888470 hasConceptScore W135888470C38349280 @default.
• W135888470 hasConceptScore W135888470C47338736 @default.
• W135888470 hasConceptScore W135888470C57879066 @default.
• W135888470 hasConceptScore W135888470C62520636 @default.
• W135888470 hasLocation W1358884701 @default.
• W135888470 hasOpenAccess W135888470 @default.
• W135888470 hasPrimaryLocation W1358884701 @default.
• W135888470 hasRelatedWork W1965556039 @default.
• W135888470 hasRelatedWork W1970281942 @default.
• W135888470 hasRelatedWork W1975138312 @default.
• W135888470 hasRelatedWork W1982499016 @default.
• W135888470 hasRelatedWork W2024005531 @default.
• W135888470 hasRelatedWork W2035897248 @default.
• W135888470 hasRelatedWork W2052122982 @default.
• W135888470 hasRelatedWork W2074541123 @default.
• W135888470 hasRelatedWork W2078953124 @default.
• W135888470 hasRelatedWork W2120398030 @default.
• W135888470 hasRelatedWork W2179320668 @default.
• W135888470 hasRelatedWork W2182784879 @default.
• W135888470 hasRelatedWork W2233519182 @default.
• W135888470 hasRelatedWork W2341657087 @default.
• W135888470 hasRelatedWork W2609047631 @default.
• W135888470 hasRelatedWork W2904212062 @default.
• W135888470 hasRelatedWork W3012207731 @default.
• W135888470 hasRelatedWork W3133214897 @default.
• W135888470 hasRelatedWork W1970412220 @default.
• W135888470 hasRelatedWork W289371953 @default.
• W135888470 hasVolume "1" @default.
• W135888470 isParatext "false" @default.
• W135888470 isRetracted "false" @default.
• W135888470 magId "135888470" @default.
• W135888470 workType "article" @default.