Re: can anyone solve this equation?

• To: mathgroup at smc.vnet.net
• Subject: [mg58056] Re: [mg57986] can anyone solve this equation?
• From: Pratik Desai <pdesai1 at umbc.edu>
• Date: Fri, 17 Jun 2005 05:19:08 -0400 (EDT)
• References: <200506160935.FAA18298@smc.vnet.net>
• Sender: owner-wri-mathgroup at wolfram.com

```Chris Chiasson wrote:

>Dear MathGroup Gurus,
>
>Can anyone solve the following equation (for theta_4)?
>
>The assumptions are in this cell (use ctrl+shift+e, paste it into the
>notebook, and then use ctrl+shift+e again):
>
>Cell["\<\
>\$Assumptions=Flatten[Append[{True},{(#1>=0&)/@{\[Alpha]},
>(#1>0&)/@{r,numcyl,Displacement\[UnderBracket]Base,SBRatio,P\[UnderBracket]0,P\
>\[UnderBracket]7,T\[UnderBracket]Intake,T\[UnderBracket]7},
>(#1>1&)/@{R\[UnderBracket]ConRodCrankArm,CR\[UnderBracket]Base,k\[UnderBracket]Air\
>\[UnderBracket]c,k\[UnderBracket]Air\[UnderBracket]e}}]];\
>\>","Input"]
>
>The equation is in the cell below (I need the solution for theta
>underbracket four):
>
>Cell["\<\
>(1/(2*(-1+CR\[UnderBracket]Base)*numcyl))*(Displacement\[UnderBracket]Base*(1+CR\
>\[UnderBracket]Base-R\[UnderBracket]ConRodCrankArm+
>CR\[UnderBracket]Base*R\[UnderBracket]ConRodCrankArm+Cos[\[Theta]\[UnderBracket]4]-CR\
>\[UnderBracket]Base*Cos[\[Theta]\[UnderBracket]4]+
>Sqrt[R\[UnderBracket]ConRodCrankArm^2-Sin[\[Theta]\[UnderBracket]4]^2]-
>CR\[UnderBracket]Base*Sqrt[R\[UnderBracket]ConRodCrankArm^2-Sin[\[Theta]\[UnderBracket]4]^2]))==\
>
>(Displacement\[UnderBracket]Base*(2^k\[UnderBracket]Air\[UnderBracket]c*(-1+\
>CR\[UnderBracket]Base)*(P\[UnderBracket]Intake/P\[UnderBracket]Exit)^(1/k\[UnderBracket]Air\
>\[UnderBracket]c)*q\[UnderBracket]LHV*
>(c\[UnderBracket]P\[UnderBracket]e+c\[UnderBracket]v\[UnderBracket]e*\[Alpha])*Cos[\[Theta]\
>\[UnderBracket]1]+2^k\[UnderBracket]Air\[UnderBracket]c*c\[UnderBracket]v\[UnderBracket]e*q\
>\[UnderBracket]LHV*\[Alpha]*
>(2-(P\[UnderBracket]Intake/P\[UnderBracket]Exit)^(1/k\[UnderBracket]Air\[UnderBracket]c)+(P\
>\[UnderBracket]Intake/P\[UnderBracket]Exit)^(1/k\[UnderBracket]Air\[UnderBracket]c)*
>R\[UnderBracket]ConRodCrankArm-(P\[UnderBracket]Intake/P\[UnderBracket]Exit)^(1/k\
>\[UnderBracket]Air\[UnderBracket]c)*
>Sqrt[R\[UnderBracket]ConRodCrankArm^2-Sin[\[Theta]\[UnderBracket]1]^2]+\
>CR\[UnderBracket]Base*(P\[UnderBracket]Intake/P\[UnderBracket]Exit)^
>(1/k\[UnderBracket]Air\[UnderBracket]c)*(-1-R\[UnderBracket]ConRodCrankArm+Sqrt[R\
>\[UnderBracket]ConRodCrankArm^2-Sin[\[Theta]\[UnderBracket]1]^2]))+
>c\[UnderBracket]P\[UnderBracket]e*(-2*(1+\
>AF)*c\[UnderBracket]v\[UnderBracket]e*(P\[UnderBracket]Intake/P\[UnderBracket]Exit)^(1/k\[UnderBracket]\
>Air\[UnderBracket]c)*T\[UnderBracket]Intake*(1+\[Alpha])*
>(1+CR\[UnderBracket]Base-R\[UnderBracket]ConRodCrankArm+CR\[UnderBracket]Base*R\
>\[UnderBracket]ConRodCrankArm+Cos[\[Theta]\[UnderBracket]1]-
>CR\[UnderBracket]Base*Cos[\[Theta]\[UnderBracket]1]+Sqrt[R\[UnderBracket]ConRodCrankArm^2-\
>Sin[\[Theta]\[UnderBracket]1]^2]-
>CR\[UnderBracket]Base*Sqrt[R\[UnderBracket]ConRodCrankArm^2-\
>Sin[\[Theta]\[UnderBracket]1]^2])^k\[UnderBracket]Air\[UnderBracket]c+
>2^k\[UnderBracket]Air\[UnderBracket]c*q\[UnderBracket]LHV*(2-(P\[UnderBracket]Intake/P\
>\[UnderBracket]Exit)^(1/k\[UnderBracket]Air\[UnderBracket]c)+
>(P\[UnderBracket]Intake/P\[UnderBracket]Exit)^(1/k\[UnderBracket]Air\[UnderBracket]c)*R\
>\[UnderBracket]ConRodCrankArm-
>(P\[UnderBracket]Intake/P\[UnderBracket]Exit)^(1/k\[UnderBracket]Air\[UnderBracket]c)*Sqrt[R\
>\[UnderBracket]ConRodCrankArm^2-Sin[\[Theta]\[UnderBracket]1]^2]+
>CR\[UnderBracket]Base*(P\[UnderBracket]Intake/P\[UnderBracket]Exit)^(1/k\[UnderBracket]Air\
>\[UnderBracket]c)*(-1-R\[UnderBracket]ConRodCrankArm+
>Sqrt[R\[UnderBracket]ConRodCrankArm^2-Sin[\[Theta]\[UnderBracket]1]^2])))))/((-1+CR\
>\[UnderBracket]Base)*c\[UnderBracket]P\[UnderBracket]e*numcyl*
>(2^k\[UnderBracket]Air\[UnderBracket]c*(-1+CR\[UnderBracket]Base)*(P\[UnderBracket]Intake/P\
>\[UnderBracket]Exit)^(1/k\[UnderBracket]Air\[UnderBracket]c)*q\[UnderBracket]LHV*Cos[\[Theta]\
>\[UnderBracket]1]-
>2*(1+AF)*c\[UnderBracket]v\[UnderBracket]e*(P\[UnderBracket]Intake/P\[UnderBracket]Exit)^(1/k\
>\[UnderBracket]Air\[UnderBracket]c)*T\[UnderBracket]Intake*(1+\[Alpha])*
>(1+CR\[UnderBracket]Base-R\[UnderBracket]ConRodCrankArm+CR\[UnderBracket]Base*R\
>\[UnderBracket]ConRodCrankArm+Cos[\[Theta]\[UnderBracket]1]-
>CR\[UnderBracket]Base*Cos[\[Theta]\[UnderBracket]1]+Sqrt[R\[UnderBracket]ConRodCrankArm^2-\
>Sin[\[Theta]\[UnderBracket]1]^2]-
>CR\[UnderBracket]Base*Sqrt[R\[UnderBracket]ConRodCrankArm^2-\
>Sin[\[Theta]\[UnderBracket]1]^2])^k\[UnderBracket]Air\[UnderBracket]c+
>2^k\[UnderBracket]Air\[UnderBracket]c*q\[UnderBracket]LHV*(2-(P\[UnderBracket]Intake/P\
>\[UnderBracket]Exit)^(1/k\[UnderBracket]Air\[UnderBracket]c)+
>(P\[UnderBracket]Intake/P\[UnderBracket]Exit)^(1/k\[UnderBracket]Air\[UnderBracket]c)*R\
>\[UnderBracket]ConRodCrankArm-
>(P\[UnderBracket]Intake/P\[UnderBracket]Exit)^(1/k\[UnderBracket]Air\[UnderBracket]c)*Sqrt[R\
>\[UnderBracket]ConRodCrankArm^2-Sin[\[Theta]\[UnderBracket]1]^2]+
>CR\[UnderBracket]Base*(P\[UnderBracket]Intake/P\[UnderBracket]Exit)^(1/k\[UnderBracket]Air\
>\[UnderBracket]c)*(-1-R\[UnderBracket]ConRodCrankArm+
>Sqrt[R\[UnderBracket]ConRodCrankArm^2-Sin[\[Theta]\[UnderBracket]1]^2]))))\
>\>","Output",
>CellLabel->"Out[40]="]
>
>
>
I am no mathematica guru, but here is my attempt.
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best regards
Pratik

--
Pratik Desai