Altair RISE

A program to recognize and reward our most engaged community members

Nominate Yourself Now!

Specifying cumulative particle size distribution

Dear EDEM community,

I am modeling materials with different size distributions in EDEM. To my knowledge, there are three different methods for specifying a particle size distribution such that there is NOT an equal probability of each size being generated:

(1) Using a normal size distribution

(2) Using a log-normal size distribution

(3) Using a user defined size distribution

The shortcoming of methods (1) and (2) is obviously that these types of distributions should be able to fit to your particle data, which is not the case for my material. Method (3) is the next option, but I have a number-based size distribution as shown in the figure below. So, ideally I would like to specify the PSD using a cumulative distribution function. Is there any way to accomplish this?

Thanks in advance for any help/suggestions!

Cheers,

Raisa

Find more posts tagged with

EDEM

English

Accepted answers

All comments

Renan

Hi Raisa,

It looks like you have the total number of particles and the frequency of each size class, which means you can calculate the total number of particles in each size class. With that information and the material density you can calculate the total mass of particles in each class from which you can easily calculate the mass density for each size class.

Best regards,
Renan

Raïsa Roeplal

Dear Renan,

Thank you for your kind suggestion. The "frequency" is not really a frequency (sorry for the confusion); it represents the probability. So for example, for the data point indicated in my picture below, it just means that 1.1% of the total number of particles has a diameter smaller than 0.47 cm. This does not tell me how many particles have a diameter of 0.47 cm.

Of course, I can think of a solution to this problem: discretize the data by making bins (a histogram) based on size and determining the mass percentage of particles in each bin. However, I would rather not do this here and was just wondering if there is any option for specifying a cumulative size distribution.

Cheers,

Raisa

Untitled.png

jerrinjobs

Dear Renan,

Thank you for your kind suggestion. The "frequency" is not really a frequency (sorry for the confusion); it represents the probability. So for example, for the data point indicated in my picture below, it just means that 1.1% of the total number of particles has a diameter smaller than 0.47 cm. This does not tell me how many particles have a diameter of 0.47 cm.

Of course, I can think of a solution to this problem: discretize the data by making bins (a histogram) based on size and determining the mass percentage of particles in each bin. However, I would rather not do this here and was just wondering if there is any option for specifying a cumulative size distribution.

Cheers,

Raisa

Hi Raisa

The input needed for EDEM size distribution is the size and mass percentage. You will have to modify your data in a way for EDEM to read it correctly.

The cumulative size distribution needs to be modified, and there is no way to import it directly.

Thanks,
Jerrin Job