Abstract: A louvre assembly (400) for a gas turbine engine bleed system comprises: an air discharge opening (401); a first louvre (402) comprising a first plurality of slats (404) each pivotably mounted to rotate about a first direction (405); and a second louvre (406) comprising a second plurality of slats (408) each pivotably mounted to rotate about a second direction (409), wherein the first and second directions (405, 409) are angled relative to each other such that bleed air exiting through the air discharge opening (401) diverges away from a central axis (410) of the louvre assembly (400).

Abstract: A method of modelling at least a part of a gas turbine engine, method including: determining whether a first match feature data entity, defining a first location where a first physical feature may associate with another physical feature of a data structure, and a second match feature data entity, defining a second location where the second physical feature may associate with another physical feature of the data structure, satisfy a first matching criterion, the data structure including: a first data entity representing a geometrical shape of the first physical feature, the first data entity being associated with the first match feature data entity; and a second data entity representing a geometrical shape of the second physical feature, the second data entity being associated with the second match feature data entity; and performing relative movement between the first physical feature and the second physical feature within a model using the determination.

Abstract: A computer implemented method of automatically designing a secondary air system for a gas turbine engine. The method comprises: receiving a geometry model of at least a part of a gas turbine engine, the geometry model including a plurality of data entities for a plurality of features of the gas turbine engine; defining a plurality of cavities using the plurality of data entities of the geometry model; determining a subset of cavities of the plurality of cavities that define at least a part of the secondary air system; and generating a secondary air system model from the determined subset of cavities that define at least a part of the second airflow system.

Abstract: A method of modelling at least a part of a gas turbine engine, method including: determining whether a first match feature data entity, defining a first location where a first physical feature may associate with another physical feature of a data structure, and a second match feature data entity, defining a second location where the second physical feature may associate with another physical feature of the data structure, satisfy a first matching criterion, the data structure including: a first data entity representing a geometrical shape of the first physical feature, the first data entity being associated with the first match feature data entity; and a second data entity representing a geometrical shape of the second physical feature, the second data entity being associated with the second match feature data entity; and performing relative movement between the first physical feature and the second physical feature within a model using the determination.

Abstract: A method of modelling at least a part of a gas turbine engine, the method comprising: preparing a model of at least a part of the gas turbine engine using a data structure including: a first set of data entities representing geometrical shapes of physical features; and a second set of data entities representing geometrical shapes of aerodynamic boundaries, the second set of data entities being used to preserve aerodynamic design intent during preparation of the model.