What does a diode connected to the center of an inductor mean?

What does a diode connected to the center of an inductor mean? Trying to do a simulation but I don't know what this kind of connection means or how they should be connected.... 

More information needed, for starters, are the inductors coupled or not.
What is the rest of the circuit around the inductor and diode,
cheers,
Richard

That means a center-tapped inductor with a diode connected in series to its center tap output.

The behavior of this circuit could be very complex and you can try to investigate the waveforms of voltage and current from the simulation result in order to understand its characteristic and what does it mean actually.

Hi Richard! Oops! here is the complete diagram... thank you!

OK, the circuit is a radio receiver, the diode is for demodulating an AM signal. The inductor will be a single coil, with the diode tapped into it part way along. The diode load appears across the coil, loading it, and dropping the Q, which impacts on selectivity.
By tapping part way down the coil, you are able, by transformer action, to step the load impedance up so that the total impedance seen across the coil is higher.
Look up tuned circuits with tapped inductors or split capacitors as a way of maintaining a high Q
Cheers,
Richard

By tapping near the earthy end of the coil, you are creating two separate circuits or coils as far as our discussion is concerned.

One circuit (or coil) consists of the full winding and the other coil consists of the few turns at the earthy end.
It does not matter if they are joined or separate. The circuit will work exactly the same.
The full winding of the coil and the capacitor pick up radio stations and produce a waveform that is identical to exactly one of the stations.
This circuit is called a TUNED CIRCUIT and the amplitude is quite high but it does not have a high current. It has very little current.
If you try to “pick off” this signal with a diode placed at the top of the coil, you will be asking the circuit to deliver a current at the same time it is delivering a voltage and it is unable to do this.
It reacts by delivering a lower amplitude (voltage) signal.
But what you have done in the process is reduce the TUNED CIRCUITS amazing ability to respond to just one radio station.
If you load the circuit, the result is 2 or more radio stations at the same time.
If you put the diode on the earth rail you get no output.
But if you put the diode a few turns up from the earth rail, you will pick up the signal and not upset the operation of the circuit.
And another amazing thing happens.
The magnetic flux from the whole coil cuts the few turns at the bottom and increases the output current. This is called TRANSFORMER ACTION
Now you have the amplitude (voltage) you need and the current you want.