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I'm currently writing a thesis. I'm simulating a problem using CFD model. The model has been validated by using it to investigate similar problem with known results. The model vs. experimental results are showing good consistency.

As for my problem, I've modeled it and I've got the results. I've spent few weeks designing, building and testing the experimental equipment but I've concluded the experimental equipment must be rebuilt using different components and I don't have time.

So, where in the paper do I report the failed experiment and how do I put it in words that it failed?

Here is the main structure of my paper.

1: Introduction

2: Literature Review

3: Method.

3:1 Model observation

3:2 Experimental observation

4: Results and discussion

4:1 Model validation

4:2 Problem Results (Here I was going to compare model vs. experiment)

4:3 Discussion

5: Conclusion and future work.

  • Did you get results that differ from the model, or can you not get any results at all? – Patricia Shanahan Apr 29 '17 at 15:43
  • I couldn't get any sensible results. The equipment is vibrating allot which have direct effect on the sensors and data acquisition. The equipment is partially controlled by motors which doesn't seem to have enough torque and the motor is changing position when load is applied. As for the force sensor I was allocated, it's just unfavorable for this kind of measurements (Weak tolerance for momentum which is unavoidable in this case). – Bjartmar Apr 29 '17 at 16:56
  • If you have not already done so, still have access to the experimental setup, and have time, try to quantify as much as possible. How much torque does the motor supply? How much is needed? Vibration amplitude and frequency? – Patricia Shanahan May 1 '17 at 12:50
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You need a slight mental twist. Your experiment was not a failure. The purpose of an experiment is to ask the real world a question, and unexpected answers from the real world are at least as interesting as ones you expected.

The question you asked the real world was "Does this experimental set-up work for Problem X?". The short answer to the question, based on your experiments, is "No". Of course, you will go into a lot more detail in your thesis.

The early sections of your thesis will be much the same as they would have been if you had got the results you expected.

In 4:2, you describe your tests of your experimental set-up. To the extent that you got results at all, you do compare them to the model.

In 4:3 you discuss what you learned from building and testing your experimental equipment. If you are getting different results from model and experiment, you need to discuss why the model is more reliable than the experiment. One learns more from unexpected results than from expected ones, so this section will be richer and more interesting than it would have been if you had got the results you expected.

Your question contains the outline for "Conclusion and future work", easily identified through the keyword "concluded":

I've concluded the experimental equipment must be rebuilt using different components

The conclusion is that the equipment you built is not suitable for your problem. The future work is to rebuild it using different components. Again, you need to go into a lot more detail. What aspects of your set-up were unsuitable? Why do you think particular changes might improve it?

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