The project deals with the development of a theoretical and experimental activity for supersonic flow phenomena in order to understand the important physical features of such flows and to establish a common database containing numerical and experimental data in order to provide specific knowledge and improve existing tools for the analysis and optimization of configurations for supersonic aircraft.
The experimental and numerical studies in this project mainly concentrated on basic supersonic phenomena such as shock boundary layer and shock vortex interactions. All the experimental data, together with many numerical data, formed a database. A common neutral data format was adopted and a tool was developed to ease the data conversion and manipulation from this common format to user formats. The database was enriched with other experimental data, including a complete data set of a supersonic transport configuration. The study showed the possibility of designing and manufacturing a wind tunnel pressure plotted model of an aeroelastic supersonic transport aircraft wing. Moreover a structural model and a series of flutter analyses in various flight regimes were produced and included in the database. A detailed experimental investigation of flow interactions at supersonic speed was carried out. 2 simple geometries were tested:
a fin (shock generator) mounted orthogonally to a flat plate;
a simple calibration model composed of an axisymmetric ogive cylinder body plus a pair of cropped delta wings.
A review of engineering tools and formulae for predicting the aerodynamic characteristics of a supersonic configuration was carried out. The capabilities of low cost preliminary design tools were evaluated and some improvement to their characteristics was achieved. Different engineering methods, based on viscous inviscid coupling between a shear layer method and an inviscid Euler code, were studied and assessed in comparison to Navier-Stokes solver. Results were produced for 3-dimensional boundary layer methods, 8 Euler plus boundary layer methods and Navier-Stokes methods. Improvements in 2-dimensional simulation techniques were achieved and the reliability of complex 3-dimensional calculations was demonstrated. New solution algorithms were also investigated. 3 special topics were also addressed:
the computation of supersonic corner flows;
the laminar to turbulent tran sition;
the modelling of turbulence for shock boundary layer interactions.
Selected and well instrumented available experiments will be initially inserted in the database; a successive enrichment will be carried out by performing new detailed flow measurements on generic models, with emphasis on pressure coefficients and the velocity field data.
Simple methods are used at the early stage of a project to define the main parameters of the aircraft configuration. Methods to estimate supersonic flow field as well as boundary layer and shock/boundary layer interaction will be analyzed. A validation assessment is nevertheless needed before using them in a shape optimization procedure.
In order to identify accurate and fully validated numerical codes for the modelling of viscous and inviscid supersonic flows, accurate tools are needed to check and calibrate the approximate methods and to check and analyse the results of the optimization process. Existing laminar and turbulent Navier-Stokes codes will be evaluated on 2-dimensional and 3-dimensional test cases, as well as Euler plus boundary layer methods. The results will be compared with experimental data made available from the database.
Funding SchemeCSC - Cost-sharing contracts
PR4 1AX Preston
10129 Torino (Turin)