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 The method is based on a semiempirical correlation of a wide range of experimental data, including many unpublished results.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 pylonmounted engine pods, with sharp or rounded lips, and with entry contraction ratios up to 1.4. Diffusers having area ratio up to 7, with semiangle 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 takeoff 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: 

Status: 

Previous Releases: 

ISBN: 

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 IHS 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 