Display WooCommerce Products by Custom Taxonomy

   $args = array(
     'posts_per_page' => -1,
     'tax_query' => array(
      'relation' => 'AND',
      array(
         'taxonomy' => 'product_cat',
                   'field' => 'term_id', //it can be name, slug or term_id
                   'terms' => 15
               )
  ),
     'post_type' => 'product',
     'orderby' => 'title,'
 );

    $products = new WP_Query( $args );

    while ( $products->have_posts() ) {
     $products->the_post();
     ?>
     <li>
         <a href="<?php the_permalink(); ?>">
             <?php the_title(); ?>
         </a>
     </li>
     <?php

 }