Typically you first enter state variable values and then request Cranium or Synapse to generate an estimated property value. Sometimes, the opposite process is desired - you specify a desired property value and ask the application to estimate the state variable values that would generate that estimate.
For example, the estimated entropy values shown below are all equal to 1000 J/kg K. Each entropy value was entered as a goal value with an input pressure starting at 100 kPa and being incremented by 20 kPa. The temperature was then varied until the goal value was matched.
The Goal Seek dialog has controls for entering an initial temperature or pressure value, a goal value, and for performing the goal seek operation.
|Temperature Control: enables you to enter a value for the temperature that will be used as either a fixed value or an initial guess.
|Pressure Control: enables you to enter a value for the pressure that will be used as either a fixed value or an initial guess.
|Independent Variable Control: enables you to select either temperature or pressure as the independent variable, i.e., the variable that will be varied to achieve the goal value.
|Property Control: displays the property being estimated.
|Goal Control: enables you to enter your goal physical property value.
|Value Control: displays the value estimated given the current temperature and pressure. This value should start approaching the goal value as the solution process proceeds.
|Delta Control: displays the difference between the goal value and the current estimated value. This value should approach zero as the solution process proceeds.
|Start Seek Button: pressing this button starts the solution process.
It is sometimes necessary to have a very good initial guess in order to find a successful goal seek solution. One way you can often get a good initial is by estimating some values at temperature values near those you expect for goal value.
You can use these estimated values as your initial guess by simply selecting them in the Estimates Dialog and pressing the Goal Seek button. The selected temperature will be assign to the Goal Seek dialog's controls.
|Getting Started using Synapse
|provides a quick tour of Synapse's capabilities including examples of chemical product design.
|Getting Started using Cranium
|provides a quick tour of Cranium's capabilities including a discussion of structure editing.
|Estimating Chemical Properties
|a short video demonstrating how to estimate the physical properties of chemicals using either Synapse or Cranium.
|Estimating Mixture Properties
|a short video demonstrating how to estimate the physical properties of mixtures using either Synapse or Cranium.