ESDU 80037: Pressure recovery of axisymmetric intakes at subsonic speeds.

Abstract:

ESDU 80037 provides a method for estimating the pressure recovery of axisymmetric intakes at subsonic speeds. The method is based on a semi-empirical correlation of a wide range of experimental data, including many unpublished results. The two main components of intake loss, associated with the lip and the diffuser portions of the intake, are considered separately. ESDU 80037 provides the data needed to estimate values for each of these components, the interaction between them, and to determine other minor components of pressure loss arising from straight portions of intake between the lip and diffuser and between the diffuser and the engine entry. The effects of nacelle incidence, which can be taken to include sideslip in crosswind conditions, are taken into account. The data apply to axisymmetric intakes, such as those on pylon-mounted engine pods, with sharp or rounded lips, and with entry contraction ratios up to 1.4. Diffusers having area ratio up to 7, with semi-angle up to 10 degrees, are covered. These ranges cover all currently practical requirements for axisymmetric intakes. The data are presented for aircraft flying at Mach numbers up to 0.8 for zero engine incidence, and (at take-off and landing speeds) for engine incidences up to 25 degrees. The calculation method applies for intake mass flows up to the choking condition. A method is included for estimating approximately, when required, the pressure losses under choked flow conditions. Two comprehensive worked examples on the use of the data are included.

Indexed under:

Details:

Data Item ESDU 80037
Format:	PDF with interactive graphs
Status:	Original, issued 01 Nov 1980 Published in Release 2000-03 (init)
Previous Releases:	None available
ISBN:	978 0 85679 320 2

The Data Item document you have requested is available only to subscribers or purchasers.

Subscribers login here.
If you are not an ESDU subscriber you can
- find out how to subscribe, or
- purchase this Data Item from the Standards Store.

The graphs listed below are available only to subscribers.

Subscribers login here.
If you are not an ESDU subscriber find out how to subscribe.

This Data Item contains 18 interactive graph(s) as listed below.

Graph	Title
Figure 1	Lip loss for sharp lip intake at zero incidence (0 ≤ M_∞ ≤ 0.4)
Figure 2	Lip loss for sharp lip intake at zero incidence (0.4 ≤ M_∞ ≤ 0.8)
Figure 3	Lip loss boundary at zero incidence
Figure 4	Mass flow function
Figure 5	Lip loss factor for rounded lips at zero incidence
Figure 6a	Choking Mach number
Figure 6b	Choking Mach number
Figure 7a	Factors in Equation (3.12) for diffuser loss
Figure 7b	Factors in Equation (3.12) for diffuser loss
Figure 8a	Factors in Equation (3.18) for diffuser loss magnification factor (attached entry flow)
Figure 8b	Factors in Equation (3.18) for diffuser loss magnification factor (attached entry flow)
Figure 9	Factor allowing for datum interaction effects between entry and diffuser
Figure 10a	Factors in Equation (3.21) for diffuser loss magnification factor (separated entry flow)
Figure 10b	Factors in equation (3.21) for diffuser loss magnification factor (separated entry flow)
Figure 11a	Intakes at incidence: circular lips
Figure 11b	Intakes at incidence: circular lips
Figure 12a	Intakes at incidence: Elliptical lips
Figure 12b	Intakes at incidence: Elliptical lips