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Phoenix
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PostPosted: Sat Mar 05, 2011 1:48 pm    Post subject: Looking for math/physics FORMULAE PERTAINING to HG Reply with quote #1   
If you have any resources for me to check out along these lines, let me
know! Calculus O.K.
Looking for all manner of stuff, wing loading, g force, wing dynamics, structural.
Please no programs, encyclopedias, joke. Just the equations, thanks!


Last edited by Phoenix on Tue Mar 08, 2011 5:29 am; edited 1 time in total
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mlbco
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Location: Sunnyvale, CA

PostPosted: Sat Mar 05, 2011 4:45 pm    Post subject: Reply with quote #2   
Here's some Matlab code to estimate a glider's polar.

Steve

%Polar Estimation MATLAB Code
%SJM 3-5-11
close all;clear all;
torad=pi/180.;
d2r=torad;
grav=32.174;
%-------------------------------------
%T2C
weight=70.0+200; %Gross weight (lb)
bref=33.5; %wing span (ft)
sref=154.0;%wing area (ft^2)
fo=1.75;%Non lifting drag area (ft^2) This accounts for pilot, downtubes, rigging, instruments, etc.
clmax=1.3; %Stall CL
clmin=0.2; %dive CL
cdo=.01; %zero lift drag for the wing section
cd2=.005; %lift dependent viscous drag for the wing section
ro=0.00237; % air density (slug/ft^3)
e=0.9; % span efficiency factor (0<e<1)
bank=0.0*torad; %bank angle (deg) (use this to estimate polar in turing flight i.e. thermalling)
%-------------------------------------
%------------------------------------------
ar=bref*bref/sref;
num=100;
dcl=clmax/num;
for i=1:num
cl=clmax-dcl*(i-1);
if(cl>clmin)
cd=fo/sref+cdo+cl*cl*(cd2+1./(pi*ar*e)); %drag coeff
vo(i)=sqrt(2.*weight/(ro*cl*sref*cos(bank)));%Airspeed at trim CL (ft/sec)
drag=0.5*ro*vo(i)*vo(i)*cd*sref; %Drag (lb)
vv(i)=(-drag*vo(i)/weight);%sink rate (ft/sec)
radius(i)=1e6;
if(bank>0)
radius(i)=vo(i)*vo(i)/(grav*tan(bank));%Turn Radius (ft)
end;
phi(i)=bank/torad;% Bank angle(deg)
ld(i)=vo(i)/-vv(i);%L/D w.r.t. air
gam(i)=atan(1/ld(i))/d2r; %Glide angle (deg)
%ld2(i)=cl*cos(bank)/cd;
end;
end;
figure(1);plot(vo/1.467,ld,'-b');zoom on;grid on; %L/D vs airspeed (mph)
figure(2);plot(vo/1.467,60*vv,'-b');zoom on;grid on; %Sink rate (fpm) vs airspeed (ft/sec)
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AIRTHUG
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PostPosted: Sat Mar 05, 2011 5:07 pm    Post subject: Reply with quote #3   
run
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(trashing the entire site in a sig after you leave..... poor form )
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SeeMarkFly
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PostPosted: Sat Mar 05, 2011 5:37 pm    Post subject: Reply with quote #4   
AIRTHUG wrote:
run
http://www.khanacademy.org
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Phoenix
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Joined: 21 Dec 2010
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PostPosted: Sat Mar 05, 2011 5:45 pm    Post subject: Reply with quote #5   
No mat lab. But I do have mathematica circa 2006. Also mathcad circa 2001.
Not into programing much, just the equations.
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Phoenix
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PostPosted: Sat Mar 05, 2011 5:50 pm    Post subject: Reply with quote #6   
SeeMarkFly wrote:
AIRTHUG wrote:
run
http://www.khanacademy.org


NICE resource, but no time to parse through it all!
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st1lgar
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PostPosted: Sat Mar 05, 2011 6:09 pm    Post subject: Reply with quote #7   
now having the polars you can calc mccready...
look here Smile
http://faculty.chicagobooth.edu/john.cochrane/research/Papers/newmcred.pdf

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George R.R. Martin
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Phoenix
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PostPosted: Sat Mar 05, 2011 7:07 pm    Post subject: Reply with quote #8   
st1lgar wrote:
now having the polars you can calc mccready...
look here Smile
http://faculty.chicagobooth.edu/john.cochrane/research/Papers/newmcred.pdf

now having the polars???? I can not decode MATLAB! I don't do programing!!!
I will read the mccready article though.
Just asking for formulae that apply to HG, (from simple stuff to polars) not the entire volume of mathematics from pythagoras to Andrew Wiles, now sorry I asked! Crying or Very sad
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Phoenix
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PostPosted: Sat Mar 05, 2011 10:30 pm    Post subject: Reply with quote #9   
deleted

Last edited by Phoenix on Sun Mar 06, 2011 1:40 am; edited 1 time in total
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Phoenix
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PostPosted: Sat Mar 05, 2011 10:30 pm    Post subject: Reply with quote #10   
Deleted

Last edited by Phoenix on Sun Mar 06, 2011 1:42 am; edited 1 time in total
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Phoenix
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PostPosted: Sat Mar 05, 2011 10:30 pm    Post subject: Reply with quote #11   
Deleted-caught by the server down

Last edited by Phoenix on Sun Mar 06, 2011 1:44 am; edited 3 times in total
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Phoenix
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PostPosted: Sat Mar 05, 2011 10:36 pm    Post subject: Reply with quote #12   
st1lgar wrote:
now having the polars you can calc mccready...
look here Smile
http://faculty.chicagobooth.edu/john.cochrane/research/Papers/newmcred.pdf
Just skimming the article, looks like something interesting to try and wrap my mind around! wtf
Thanks, but I'm not that much of an XC guy.
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rongleason
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PostPosted: Sun Mar 06, 2011 7:09 am    Post subject: formula Reply with quote #13   
checking account = x
start HG
buy equipment, buy new vehicle, convince the SO to camp and drive

checking account now = x-(HG equip - vehicle - gifts to keep SO happy) + 50% of usual paycheck due to number of sick days taken

long HG trips, quit job, SO leaves etc

checking account has been closed and live off the cash in the wallet
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