viscosity for isopentane and pentane are incorrect

[krule012]

The calculated viscosity in coolprop for both isopentane and n-pentane seems incorrect (specifically below 200 K). I would expect the gradient in viscosity to be larger for both pure fluids below 200 K. I don't have another data source that I can compare this to. Could you verify against pure fluid properties from NIST?

[ibell]

First off, this is deprecated repository for CoolProp; issues should be sent here: https://github.com/coolprop/coolprop/issues Where is your data? :) CoolProp implements the models listed on each of the info pages: http://www.coolprop.org/fluid_properties/fluids/n-Pentane.html#fluid-n-pentane and ECS with these parameters for isopentane: http://www.coolprop.org/fluid_properties/fluids/Isopentane.html#fluid-isopentane . Feel free to provide a better model, but I do not believe than any exists.

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On Fri, Aug 25, 2017 at 9:56 AM, krule012 ***@***.***> wrote: The calculated viscosity in coolprop for both isopentane and n-pentane seems incorrect (specifically below 200 K). I would expect the viscosity for isopentane to be greater than n-pentane at temperatures below 200 K. I would also expect the gradient in viscosity to be larger for both pure fluids below 200 K. — You are receiving this because you are subscribed to this thread. Reply to this email directly, view it on GitHub <#269>, or mute the thread <https://github.com/notifications/unsubscribe-auth/ABxha5Cr8FbHAsyNxuAs-GogSiyD4jdPks5sbu7DgaJpZM4PC2Zu> .

[krule012]

Ian, I observed a discrepancy between the calculated viscosity curve from coolprop as compared with refprop. Unfortunately I am unable to provide a better source for this calculation. Do you have a license for Refprop that you could use to run a comparison? I've been using coolprop extensively, no better free source for thermophysical fluid properties exists (so far as I know). Thank you for all of your contributions! On Aug 27, 2017 1:05 PM, "Ian Bell" <notifications@github.com> wrote: First off, this is deprecated repository for CoolProp; issues should be sent here: https://github.com/coolprop/coolprop/issues Where is your data? :) CoolProp implements the models listed on each of the info pages: http://www.coolprop.org/fluid_properties/fluids/n-Pentane. html#fluid-n-pentane and ECS with these parameters for isopentane: http://www.coolprop.org/fluid_properties/fluids/Isopentane. html#fluid-isopentane . Feel free to provide a better model, but I do not believe than any exists.

On Fri, Aug 25, 2017 at 9:56 AM, krule012 ***@***.***> wrote: The calculated viscosity in coolprop for both isopentane and n-pentane seems incorrect (specifically below 200 K). I would expect the viscosity for isopentane to be greater than n-pentane at temperatures below 200 K. I would also expect the gradient in viscosity to be larger for both pure fluids below 200 K. — You are receiving this because you are subscribed to this thread. Reply to this email directly, view it on GitHub <#269>, or mute the thread <https://github.com/notifications/unsubscribe-auth/ABxha5Cr8FbHAsyNxuAs-

GogSiyD4jdPks5sbu7DgaJpZM4PC2Zu>

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[ibell]

Actually, I am now a developer of REFPROP. Do you know what models are used in REFPROP for these two fluids?

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On Sun, Aug 27, 2017 at 4:00 PM, krule012 ***@***.***> wrote: Ian, I observed a discrepancy between the calculated viscosity curve from coolprop as compared with refprop. Unfortunately I am unable to provide a better source for this calculation. Do you have a license for Refprop that you could use to run a comparison? I've been using coolprop extensively, no better free source for thermophysical fluid properties exists (so far as I know). Thank you for all of your contributions! On Aug 27, 2017 1:05 PM, "Ian Bell" ***@***.***> wrote: First off, this is deprecated repository for CoolProp; issues should be sent here: https://github.com/coolprop/coolprop/issues Where is your data? :) CoolProp implements the models listed on each of the info pages: http://www.coolprop.org/fluid_properties/fluids/n-Pentane. html#fluid-n-pentane and ECS with these parameters for isopentane: http://www.coolprop.org/fluid_properties/fluids/Isopentane. html#fluid-isopentane . Feel free to provide a better model, but I do not believe than any exists. On Fri, Aug 25, 2017 at 9:56 AM, krule012 ***@***.***> wrote: > The calculated viscosity in coolprop for both isopentane and n-pentane > seems incorrect (specifically below 200 K). I would expect the viscosity > for isopentane to be greater than n-pentane at temperatures below 200 K. I > would also expect the gradient in viscosity to be larger for both pure > fluids below 200 K. > > — > You are receiving this because you are subscribed to this thread. > Reply to this email directly, view it on GitHub > <#269>, or mute the thread > <https://github.com/notifications/unsubscribe-auth/ABxha5Cr8FbHAsyNxuAs- GogSiyD4jdPks5sbu7DgaJpZM4PC2Zu> > . > — You are receiving this because you authored the thread. Reply to this email directly, view it on GitHub <#269 (comment)>, or mute the thread <https://github.com/notifications/unsubscribe-auth/Ad5m0QsiBFrAMqnSwyF1R_ g7qmULklL0ks5sca_ZgaJpZM4PC2Zu> . — You are receiving this because you commented. Reply to this email directly, view it on GitHub <#269 (comment)>, or mute the thread <https://github.com/notifications/unsubscribe-auth/ABxha7jbSuUYBNshuWFsGigmkGgm4GaVks5scebhgaJpZM4PC2Zu> .

[krule012]

Based on the nature of your response, I would guess the same as Coolprop... The curves I had referenced from Refprop we're from an older version (I think v8 or v9). I had generated these back during my graduate research work. I'll go ahead and update my model using the curves from coolprop then. Hopefully I didn't waste too much of your time. I'll make sure to post any future issues at the link you provided below. The help link I had used was from the "v4 documents" website. On Aug 27, 2017 5:08 PM, "Ian Bell" <notifications@github.com> wrote: Actually, I am now a developer of REFPROP. Do you know what models are used in REFPROP for these two fluids?

On Sun, Aug 27, 2017 at 4:00 PM, krule012 ***@***.***> wrote: Ian, I observed a discrepancy between the calculated viscosity curve from coolprop as compared with refprop. Unfortunately I am unable to provide a better source for this calculation. Do you have a license for Refprop that you could use to run a comparison? I've been using coolprop extensively, no better free source for thermophysical fluid properties exists (so far as I know). Thank you for all of your contributions! On Aug 27, 2017 1:05 PM, "Ian Bell" ***@***.***> wrote: First off, this is deprecated repository for CoolProp; issues should be sent here: https://github.com/coolprop/coolprop/issues Where is your data? :) CoolProp implements the models listed on each of the info pages: http://www.coolprop.org/fluid_properties/fluids/n-Pentane. html#fluid-n-pentane and ECS with these parameters for isopentane: http://www.coolprop.org/fluid_properties/fluids/Isopentane. html#fluid-isopentane . Feel free to provide a better model, but I do not believe than any exists. On Fri, Aug 25, 2017 at 9:56 AM, krule012 ***@***.***> wrote: > The calculated viscosity in coolprop for both isopentane and n-pentane > seems incorrect (specifically below 200 K). I would expect the viscosity > for isopentane to be greater than n-pentane at temperatures below 200 K. I > would also expect the gradient in viscosity to be larger for both pure > fluids below 200 K. > > — > You are receiving this because you are subscribed to this thread. > Reply to this email directly, view it on GitHub > <#269>, or mute the thread > <https://github.com/notifications/unsubscribe-auth/ABxha5Cr8FbHAsyNxuAs- GogSiyD4jdPks5sbu7DgaJpZM4PC2Zu> > . > — You are receiving this because you authored the thread. Reply to this email directly, view it on GitHub <#269 (comment)>, or mute the thread <https://github.com/notifications/unsubscribe-auth/Ad5m0QsiBFrAMqnSwyF1R_ g7qmULklL0ks5sca_ZgaJpZM4PC2Zu> . — You are receiving this because you commented. Reply to this email directly, view it on GitHub <#269 (comment)>, or

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[thorade]

replaced by
CoolProp/CoolProp#1541
please close this issue here