Conical Shock Tables

25
_.. COPV NASASP-3004 iii'_, NATIONAL AERONAUTICS AND SPACE ADMINISTRATION

Transcript of Conical Shock Tables

Page 1: Conical Shock Tables

_.. COPV

NASASP-3004

iii'_,

NATIONAL AERONAUTICS AND SPACE ADMINISTRATION

Page 2: Conical Shock Tables

Foreword

THIs REPORT PRESENTS, in tabular form, the results of

the calculation of supersonic flow fields about right circular cones at zero angle

of attack. These calculations were performed using the Taylor and Maceoll

theory. Numerical integrations were performed using the Runge-Kutta method

for second-order differential equations.

Results were obtained for cone angles from 2.5 ° to 30 ° in regular increments

of 2.5 °. For each of these 12 cone angles, a series of 16 problems was computed

at nominal free-stream Mach numbers from 1.5 to 20.0. The free-stream Mach

number was not increased in even increments, but the same values were used

for each cone angle. In all calculations, the desired free-stream Mach number

was obtained to six or more significant figures.

The data listed in this report ard essentially the same as those of Zden_k

Kopal's Tables of Supersonic Flow Around Cones (M.I.T. Tech. Rep. No. 1,

1947). They differ from Kopal's work only in the manner of presentation and

by the use of a specific heats ratio of 1.4 instead of 1.405. This report repre-

sents a complement to NASA SP-3007 in which the flow field about cones at

small angles of attack in a body-fixed coordinate system is tabulated.

.lo

111

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ContentsPAGE

FOREWORD ..................................................... III

INTRODUCTION .................................................. 1

SYMBOLS ....................................................... 2

SOLUTION OF THE EQUATIONS ..................................... 3

DISCUSSION OF TABLES ........................................... 4

REFERENCES .................................................... 5

TABLE

I,--VALUES FOR MINIMUM FREE-STREAM MACH NUMBER ............ 6

2.--VALUES OF P,/P ............................................ 7

3.--VALUES OF Ps/9 ............................................. 8

4.--VALUES OF TJT ............................................ 9

5.--VALUES OF AS/R ............................................ 10

6.--VALVES OF M* AT CONE SURFACE ............................ 11

7.--VALUES OF M AT CONE SURFACE ............................ 12

8.--VALUES OF fl AT CONE SURFACE ............................. 13

9.--VALVES OF SURFACE PRESSURE COEFFICIENT ................... 14

10.--SHOCK=WAVE RESULTS FOR MINIMUM FREE-STREAM MACH

NUMBER .................................................

11.--VALUES OF SHOCK WAVE ANGLE 8_ ............................

12.--VALUES

13.--VALUES

14 .--VALUES

15.--VALUES

16._VALUES

17.--VALUES

15

16

17OF P_/P ............................................

OF pw/p ............................................. 18

OF T./T® ........................................... 19

OF M_, IMMEDIATELY BEHIND SHOCK WAVE ............. 20

OF M IMMEDIATELY BEHIND SHOCK WAVE .............. 21

OF #, IMMEDIATELY BEHIND SHOCK WAVE .............. 22

V

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TAB LE S

18- 34.--0,= 2.5°;

35- 51.--0,= 5.0o;

52- 68.--0,= 7.5o;

69- 85.--0,= lO.O°;

86-102.--0,= 12.5°;

103-119.--8,=15.0°;

120-136.--#,= 17.5 °;

137-153.--#,=20.0°;

154-170.--#_=22.5 °;

171-187.u#,=25.0°;

188-203.--8,=27.5°;

204-219.--8,=30.0°;

Con@al

M®----1.0121844

M®=1.0383341

M®=1.0735583

M®=1.1159051

M®=1.1643198

M®----1.2182190

211/.=1.2773745

M®=1.3419094

M®=1.4123337

M®=1.4895952

M®=1.5751393

M®=1.6710795

Flow Field

PAGES

to 20.0 ...................... 23-56

to 20.0 ...................... 57-90

to 20.0 ...................... 91-124

to 20.0 ...................... 125-158

to 20.0 ...................... 159-192

to 20.0 ...................... 193-225

to 20.0 ...................... 226-258

to 20.0 ...................... 259-291

to 20.0 ...................... 292-324

to 20.0 ...................... 325-357

to 20.0 ...................... 358-389

to 20.0 ...................... 390-421

vi

Fi!

iilI!l !

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Introduction

THE SOLUTION of supersonic flow

fields by the method of characteristics requires

that the flow conditions along a starting line in

the flow field be known. For sharp-nosed bod-

ies of revolution, this information is usuallyobtained from the solution of the flow field

about circular cones. During the process of

setting up a program for treating bodies of

revolution by the method of characteristics, it

was decided to compute the starting flow field

rather than use the tables published by Kopalin references 1 and 2.

With these programs available, it appeared

desirable to prepare a set of cone tables for

cones at small angles of attack in a body-fixedcoordinate system. In order not to restrict the

Mach numbers to those of references 1 and 2,this required also a set of cone tables for the

case of zero angle of attack. This latter set is

presented in this report; the angle-of-attackcase will be covered in reference 3. This

present set of tables differs from those of

reference 1 only in the manner of presentation

and the value of specific heats ratio "y. In all

of the present calculations, the ideal gas value

of _= 1.4 has been usedlOne of the uses envisioned for the results con-

tained herein is in types of solutions of which

the shock-expansion theories are typical. Thus,

the minimum cone angle was 2.5 ° and this was

increased by increments of 2.5 ° to a maximum

cone angle of 30 ° (a total of 12 cone angles).

For each of the cone angles, results were com-

puted for a constant series of free-stream Mach

numbers from 1.5 to 20. In addition, a solu-

tion was computed which yielded the minimum

free-stream Mach number for a completely

supersonic conical flow field (u,=_/_)- This

was the lowest value of M® for which anysolutions were obtaine& Consequently, for

cone angles of 27.5 ° and 30 °, the solutions at afree-stream Mach number of 1.5 were not

computed.

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Symbols

speed of sounda nondimensional speed of sound, a/V,

a* critical speed of sound

Cp pressure coefficient,--AP/qM_ critical Mach number (see eq. (7)), 17/_*

M Mach number, 17/a

P pressureq free-stream dynamic pressure, p/2V_

r,x cylindrical coordinate axes, with origin

at tip of cone; x-axis=cone axis

R universal gas constant

AS increase in entropy

T absolute temperature

u, v velocity components, dimensional (fig. 1)u nondimensional velocity along conical ray

line in spherical coordinate system

(fig. 1), u/V,v nondimensional velocity normal to con-

ical ray line in spherical coordinate

system, _/'_7_V resultant nondimensional velocity at

any conical ray line, _/_z

V velocity (dimensional)

_t limiting velocity due to expansion into

a vacuum

ratio of specific heats, cp/co; ideal gasvalue = 1.4

Mach angle

_b, flow direction angle, angle between velo-

city vector V and cone axis

v density

0 conical ray angle, from cone axis

Subscripts:s denotes values at cone surface

co

conditions back of shock wave

free-stream condition

M_

Shock

ShockWaVe

FIGVR_ 1.--Coordinate System.

line

-'Characteristic

line

rl

ii'1

Page 7: Conical Shock Tables

Solution of the

THE DERIVATIONS of the basic

equations for the conical flow problem are

given quite adequately in reference 1 and will

not be repeated here. The differential equa-tion that is the formulation of the conical

flow problem in a spherical coordinate system(fig. 1) is:

d_u . a_(u+v cot 0)dO2 -f-u= v--__-_ . (1)

where

and

du

v=_-_ (2)

a2----_-_ (1--u2--V _) (3)

In the foregoing equations, all velocities are

nondimensionalized, as in reference 1, by

dividing them by the limiting velocity attain-able by adiabatic expansion into a vacuum.

This system of computation was used, even

though the results are later transposed intoanother reference system, in order to make use

of the parameters in reference 1 as convenient

guides in setting up the numerical calculations.

Boundary conditions must be prescribed

along with equations (1) to (3), and they are

(4)

at the surface of the cone. The upper boundary

condition is found by requiring the results ob-

tained from the integration of equation _1) to

satisfy the Rankine-Hugoniot equations whichcan be expressed as

tan O_ "Y-1 u2--1 (5)_+ 1 uv

When equation (5) is Fulfilled by the results

from equation (1) the free-stream .Mach number

is given by

Equations

M / 2 u 2®_"VT--1 cos 2 O--u s (6)

The solutions of equation (1) presented

herein were obtained using the Runge-Kutta

integration method. Computation was started

at the solid surface of the cone by specifying avalue of u, and ended when the shock-wave

conditions were satisfied. Integration step

size investigations, which are not included

herein, indicate that the maximum integration

error is less that 5X10 -8 at any point in any

solution. The Rankine-Hugoniot conditionswere satisfied to ± 2 X 10 -7.

The method of solution outlined does not

yield a desired arbitrary frec-stream Mach

number without a priori knowledge of the

value of u, that should be specified. Therefore,an iteration on u_ was included in the procedure

in order that both cone angle and free-streamMach number could be specified.

Integration of equation (1) yields values of

u, v, and a at each conical ray angle 0. Theseresults are transformed into the more usable

forms of M*, _1, and _ in the following manner:

M, V /_,+1, =h_= _/_:-_ (u_+e) (7)

since

and the flow direction angle ¢1 is

Furthermore,

¢l=0 + tan_ 1v_t

_= sin-_/ a_u_+v _

However, due to space limitations, the values

of the Mach angle g will be presented _th the

small-angle-of-attack results.

Page 8: Conical Shock Tables

4

Discussion

IT HAS BEEN ASSUMED that all

of the cones are terminated at a base diameter

of unity and the geometric location of the

left-running characteristic line emanating from

this point has been computed. These results

are given in an x,r cylindrical coordinate

system that has its origin at the cone vertex.Furthermore, this characteristic line was built

up using the basic inte.gration step size during

the integration and cannot be duplicated

exactly using the tabulated values. By meansof a base diameter ratio it is possible to pro-

portion the locations of these characteristic

points on a cone of any other size. Of course,._y/_, ¢1, and u stay constant since the conical

ray angles do not change.The tables for the individual solutions were

printed directly from the machine calculationsand were not converted to decimal form. The

leading sign is the algebraic sign of the quantity.

The next eight digits that represent the

size of the quantity are considered to be

0.xxxxxxxx. Coming last are an algebraic

sign and two digits that are the exponent of

10 _-xXby which the size of the quantity mustbe multiplied to obtain the correct decimal

point location. Thus a number that is printedin the machine code as --47168732+00 is

read as --0.47168732. The angular increments

at which the tables are printed generally aredecreased as the flow field is traversed. This

was done to keep the incremental distance

along the characteristic line from increasing

continuously. In the tables, the quantities

M*, ¢,, x, and r are listed as functions of the

conical ray angle 8, starting at the cone surface

and terminating at the shock wave; x and r

are the coordinates (in the cylindrical coordinate

of Tables

system) of the characteristic starting line incone base calibers while M* is the resultant

nondimensionalized velocity and ¢1 is the flowdirection angle in radians. The end results

given with each table (AS/R, P,/P®, p,/p®,and T,/T._) were computed using the integrated

results with shock wave and isentropic equations

(ref. 4). The summary tables for surface

conditions were tabulated by hand from the

machine printed individual tables and are

given in decimal form.

Table 1 gives a summary of the surfaceresults of the calculations for the minimum

free-stream Mach number. In tables 2 through9 are summarized some of the surface results

for the cones in which the free-stream Mach

number was specified. These results are tabu-

lated for each cone angle as a function of thenominal free-stream Mach number. The itera-

tion procedure mentioned earlier producedfree-stream Mach numbers for all solutions

that correspond to the nominal values to six or

more significant figures. Shock-wave anglesand flow results immediately behind the shock

wave are given in table 10 for the minimumfree-stream Mach number solutions. Tables

11 through 17 give shock-wave angles and flow

parameters immediately behind the shockwave for all solutions in which the free-stream

Mach number was specified. Results for the

complete flow field of each calculation are

given in tables 18 through 219. In thesetables, the results are tabulated starting at the

cone surface and proceeding through the flowfield to the shock wave. The free-stream

Mach number listed with each of these tables

is the exact value computed from the Rankine-

Hugoniot equations.

Page 9: Conical Shock Tables

References1. KOPAL, ZDEN']_K: Tables of Supersonic Flow Around Cones. Massachusetts Institute

of Technology, Tech. Rep. No. 1, 1947.

2. KOPAL, ZDE.X_K: Tables of Supersonic Flow Around Yawing Cones. MassachusettsInstitute of Technology, Tech. Rep. No. 3, 1947.

3. SIMs, JosEP_ L.: Tables for Supersonic Flow Around Right Circular Cones at Small

Angle of Attack. NASA SP-3007, 1964.4. AMES RESEARCH STAFF: Equations, Tables and Charts for Compressible Flow. NACA

Rep. 1135, 1953.

Page 10: Conical Shock Tables

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Page 12: Conical Shock Tables

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Page 14: Conical Shock Tables

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Page 16: Conical Shock Tables

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Page 17: Conical Shock Tables

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Page 18: Conical Shock Tables

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Page 19: Conical Shock Tables

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Page 21: Conical Shock Tables

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Page 22: Conical Shock Tables

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Page 23: Conical Shock Tables

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Page 24: Conical Shock Tables

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Page 25: Conical Shock Tables

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